You don’t need to travel deep into the cosmos to discover otherworldly sights. Here on Earth, curious travelers can find an abundance of strange natural attractions that appear to belong to another planet. Here are seven of the world’s most bizarre landforms.

Catedral de Marmol – Patagonia, Chile

On the western shores of Chile’s Lake General Carrera sits a natural wonder consisting of spellbinding caverns, sculpted pillars, and vaulted ceilings. Made of calcium carbonate, the Catedral de Marmol (Marble Cathedral) was carved over millennia by a reaction between the lake’s waters, rocks, and glacier movement. In the morning, the caverns give off a celestial blue hue, the result of light reflecting off the lake’s deep turquoise color. When water levels recede during winter, lower sections of the caves that are usually hidden come into view. 

To experience the beauty and serenity of this natural cathedral, you’ll need to hop on a boat or paddle a kayak. Tours depart from the lakeside town of Puerto Rio Tranquilo.

Chocolate Hills – Bohol Island, Philippines

Spreading across the center of Bohol Island, the Chocolate Hills are certain to whet your appetite for adventure. There are estimated to be over 1,200 hills (or more) in this mystical Philippine landscape. Ranging in height from 100 to 395 feet, the hills are actually leftover limestone deposits from a period when the island’s rivers flowed above sea level. At the end of the dry season (typically early May), the hills turn brown to resemble oversized truffles, hence their name. 

A great place to observe the mounds is to climb the 214 steps to the Chocolate Hills Complex, located between the towns of Batuan and Carmen. At the top, visitors can contemplate the local legends surrounding their formation — one implies that the hills were formed during a brawl between two giants, while another claims that they are the tears of a giant pining for a love interest.

Dallol Volcano – Danakil Depression, Ethiopia

At first sight, you’d be forgiven for thinking that the psychedelic colors, acidic ponds, and hot springs of Dallol Volcano were part of a 1960s album cover. Located in a remote part of northeast Ethiopia, this is the world’s lowest subaerial volcano discovered to date, extending 410 feet below sea level. With average daily temperatures exceeding 106 degrees Fahrenheit, it’s also one of the hottest places on Earth. 

The dramatic landscape is caused by an active volcanic area situated under miles-deep salt deposits. Supersaturated brine pushes through the hot springs, then evaporates to leave a kaleidoscope of salt formations. Guided excursions to Dallol are possible, although they aren’t for the faint of heart due to the extreme climate and remote location. 

Darvaza Gas Crater – Karakum Desert, Turkmenistan

Journey into the heart of Turkmenistan’s Karakum Desert, and you’ll arrive at what locals like to call the “Door to Hell.” Characterized by dancing flames and crackling fire, the Darvaza Gas Crater appears to be a portal into the netherworld. This 226-foot-wide and 98-foot-deep crater was created in 1971 when Soviet geologists arrived in search of gas and oil. They penetrated a subterranean cave, which quickly collapsed, swallowing their equipment with it. 

What’s left is an eerie depression with flames caused by natural gas escaping from the encircling rock. When the gas rises, it reacts with the oxygen in the atmosphere and bursts into flames. Incredibly, Canadian explorer George Kourounis successfully traversed and descended into the crater. While not recommended to the average tourist, camping at the edge of the phenomenon is allowed. 

Fairy Chimneys – Cappadocia, Turkey

Turkey’s semi-arid central region of Cappadocia is famous for its distinctive rock formations known as Fairy Chimneys. The rocks could be a movie set conjured up by Salvador Dalí and Walt Disney, but they are actually pillars eroded over centuries following volcanic eruptions. 

This UNESCO World Heritage Site isn’t just something spectacular to look at, either. During the Roman occupation, Christians escaped to the Cappadocian town of Göreme to take advantage of the chimneys’ soft crust to build homes and churches. Soon, underground cave cities began to form in Derinkuyu and Kaymakli. Nowadays, it’s even possible to sleep inside some of the chimneys. Alternatively, a Cappadocia hot air balloon ride promises an unparalleled bird’s-eye view. 

Giant’s Causeway – County Antrim, Northern Ireland

Looking across the Atlantic Ocean from Northern Ireland’s northern coastline, Giant’s Causeway is a mesmerizing collection of some 40,000 hexagonal basalt columns. According to local legend, Irish giant Finn McCool made the causeway to cross the Irish Sea to face his Scottish rival, Benandonner. A competing legend, as detailed in an 1830 poem by Irish author Mary Anne, claims it was built for love rather than battle. 

Scientific evidence, however, tells us that it appeared almost 60 million years ago, when Ireland was still connected to North America. As European lands began to break away from the Americas, huge rifts formed on Earth’s surface. Cracks then appeared, through which flowed lava and molten rock. When the lava reached the sea, it cooled and turned into columns. Visitors to the UNESCO-protected site can walk across the columns, follow nature trails, and explore interactive exhibits at the visitor center. 

Zhangye Danxia Landform Geological Park – Gansu Province, China

Often called the “Rainbow Mountains,” this series of multicolored hills in China’s Zhangye Danxia Landform Geological Park come in stunning shades of blues, greens, reds, and yellows. The mesmeric landforms are cretaceous sandstones and siltstones that appeared prior to the formation of the Himalayas. Their striking colors are the result of the iron and other trace minerals found within the sand and silt. Several million years ago, a collision between the Indian Plate and Eurasian plate forced the mountains upwards and thus exposed rock formations once hidden beneath the surface. 

Appreciating the mountains is easy via a network of walking paths and viewing platforms. Visitors can admire curiously named mountains, like “A Dragon Playing with Fire”, “Monkeys Rush into the Sea of Fire,” and “Sleeping Beauty.”

Even if you’re not an avid hiker or climber, chances are you’ve heard of mountain ranges like the Andes, the Rockies, the Alps, and the Himalayas (home to Earth’s highest peak, Mount Everest). Perhaps you’re even familiar with the Seven Summits — the tallest peaks on each continent. But if you’re looking to venture off the beaten path, check out these six lesser-known mountain ranges around the world.

Lebombo Mountains – Eswatini, Mozambique, and South Africa

This long, narrow mountain range in Southern Africa gets its name from the Zulu word for “big nose,” ubombo. Although the mountain range doesn’t rise more than 2,600 feet, the several rivers — such as thePongola, Usutu, and Ingwavuma — which cut through the range have created some of the most impressive gorges in the world. The dense tropical forest growth on the Lebombo Mountains thins out at lower elevations, where you can see flora and fauna characteristic of a savanna. Indeed, the mountain range’s close proximity to Kruger National Park makes it an ideal location for a safari. Visitors can go to see the big five: lions, leopards, rhinos, elephants, and buffaloes.

Mocho Mountains – Jamaica

Although the Blue Mountains are Jamaica’s largest range, most of the island is mountainous and home to other, smaller mountain ranges. Located in the northern part of Clarendon Parish, along the southern portion of the island, the Mocho Mountains are Jamaica’s geographical center. They reach a maximum elevation of 1,430 feet above sea level. While this area was once full of lush tropical rainforests, unfortunately, years of farming and extreme weather have changed that.

Baudó Mountains – Colombia

The dramatic seaside cliffs of the Baudó Mountains are an extension of the isthmus of Panama along Colombia’s Pacific coastline. Although this range is small compared to the Cordillera Occidental of the Andes, which lie in the center of the country, it’s home to the Atrato River, one of the fastest flowing rivers in the world. Currently, plans are in the works to increase tourism along the entire Baudó Mountains coastal region. Look for the construction of a new port to attract tourists who want to go whale watching.

Wicklow Mountains – Ireland

When you think of the Emerald Isle, you likely think of rolling hills and seaside cliffs. Ireland is full of landscapes that make you grab your camera, and one of those is the Wicklow Mountains located outside of Dublin. This small mountain range only rises a little more than 3,000 feet above sea level, but its infamous history and easy access make it the perfect mountain range to visit. Today, the majority of the Wicklow Mountains lie within a protected national park, where visitors can hike, camp, and enjoy water sports in the range’s abundant lakes and rivers.

Glarus Alps – Switzerland

You’ve heard of the French Alps and the Swiss Alps, but you might not know that these broad references include dozens of mountain ranges across Europe. Located in central Switzerland, the glacier-covered Glarus Alps are one of these ranges. You can find great ski resorts, health resorts, and ample hiking opportunities throughout the Alps, but the Glarus range has some special characteristics.

First, the Glarus Alps rise more than 10,000 feet, with their highest point, Tödi, at almost 12,000 feet. Also, they are part of the Swiss Tectonic Arena Sardona, which has been a UNESCO World Heritage site since 2008. This area is one of the places on earth where you can see how mountains erupt when continents, or tectonic plates, collide. That makes it a great locale to mix a family ski vacation with some science education. Additionally, the Glarus Alps are also home to the largest landslide in the region since the end of the Ice Age.

Hijaz Mountains – Saudi Arabia

The Hijaz Mountains follow the Red Sea’s coast along the western side of the Arabian Peninsula. This mountain range is home to Islam’s second holiest city, Medina, where Muhammad established the first Muslim community. Muslims from around the world travel to Medina on a pilgrimage. The Hejaz Mountains are also home to Jeddah, known as Saudi Arabia’s cosmopolitan city. Jeddah is a port city on the Red Sea, which typically serves as the gateway to those who plan to visit Mecca and Medina’s waterfront resorts and world-class dining.

Earth is home to thousands of meandering rivers, each of which plays a vital role in the lives of animals, ecosystems, and people. Often called the “arteries of the world,” rivers help to connect major cities and remote settlements and serve as major trade and tourism travel routes. As well as being important to our planet, many of these water bodies are not only breathtakingly beautiful, but are also responsible for the birth of modern civilizations. Here, we’ll take a look at the world’s 10 longest rivers. 

10. Amur River – China, Mongolia, and Russia (2,761 Miles)

The Amur River (known as Heilong Jiang in China) forms a natural border between the unspoiled wilderness of northeast China and southeast Russia. The river starts its course in the steppes of Mongolia and empties into the Strait of Tartary, over 2,700 miles to the east. Encompassing the river is an enormous region of pristine grasslands and virgin forests. In this largely untouched ecosystem, some 6,000 plant species thrive, including the Korean pine and wild ginseng. It’s also a natural habitat for approximately 600 bird species, 200 mammals, and 130 types of fish. Some of the riverbed’s most well-known residents are the endangered Amur tigers and Amur leopards.  

9. Congo River – Central Africa (2,900 Miles)

Originating in a continental rift zone called the East African Rift, the Congo River consists of nearly 3,000 miles of wild rapids, waterfalls, gorges, lakes, and gentle currents. It is the only major river on Earth to cross the equator twice, as it passes through the Democratic Republic of Congo as well as countries such as Cameroon, Zambia, and Angola. The Congo is also the world’s deepest river, reaching depths of up to 722 feet. Humans have inhabited the river and surrounding Congo Basin for some 50,000 years. Today, it helps to provide freshwater and food to around 80 million people. The basin is also home to hundreds of wildlife species, including forest elephants and mountain gorillas.

8. Paraná River – Argentina, Brazil, and Paraguay (3,032 Miles)

The name of South America’s second-longest river means “like the sea” in the Tipu-Guarani language. Beginning at the confluence of Brazil’s Rio Grande and Paranaiba rivers, the Paraná River forms a water border between Brazil and Paraguay, as well as Paraguay and Argentina. After flowing through the Argentine city of Rosario, it converges with the Uruguay River to form the Río de la Plata estuary. The Paraná is home to the Itaipu Dam, one of the largest hollow gravity dams in the world. One of the river’s main tributaries is the Iguazú River on the Argentina-Brazil border, which creates the spectacular, UNESCO-listed Iguazú Falls.

7. Ob River – Kazakhstan and Russia (3,362 Miles)

Emerging in the Altai Mountains and flowing north to the Arctic Sea, the Ob River is one of Siberia’s major transportation routes. Frozen much of the year, it is typically only navigable for between 150 to 190 days annually. The river is used primarily for drinking water, irrigation, fishing, and hydroelectric energy. The landscapes surrounding the Ob vary from swampy forests and marshland in the central region of Kazakhstan and Russia to swathes of barren, icy tundra in the north. Set along the riverbanks are some of Russia’s main industrial and agricultural centers. Among these is Novosibirsk, the country’s third-largest city, whose growth was fuelled by the introduction of the Trans-Siberian Railway.

6. Yellow River – China (3,395 Miles)

The Yellow River (also known as the Huang He) is China’s second-longest river. It’s named for the silt in the water that produces a yellow-brown color and the yellow-hued residue left behind after it overflows. Beginning in the Bayankala Mountains, the river weaves through nine provinces to the Bohai Sea. As the birthplace of Chinese civilization, the Yellow River is often called the “Mother River.” Villages began to appear on its riverbanks sometime between 2100 and 1600 BCE, culminating in the formation of the Xia Dynasty, which was the first of China’s ancient dynasties. Visitors can get a glimpse into the country’s diverse history and culture on multi-day river cruises.

5. Yenisei River – Mongolia and Russia (3,442 Miles)

From the headwaters of the Selenga River in Mongolia, the Yenisei River begins its meandering course through Siberia to the Arctic waters of the Kara Sea. On its journey of nearly 3,500 miles, the river passes varied landscapes, including grasslands, taiga boreal forests, and tundra. The Yenisei is a relatively shallow river, but it flows into Lake Baikal, which is the world’s deepest and oldest lake. Starting in the 1600s, Russians have used the river for hydroelectricity, oil, and the lumber trade. Prior to this, it was inhabited by ancient tribes such as the Ket, Kott, and Yogh. In 2001, four adventurers and filmmakers battled frozen waters and subzero temperatures to become the first group to navigate the entire river. 

4. Mississippi-Missouri River – United States (3,902 Miles)

Winding through the American heartland, the iconic Mississippi River flows through no less than 10 states on its journey from Lake Itasca in northern Minnesota south to the Gulf of Mexico below New Orleans, Louisiana. A major tributary of the Mississippi is the Missouri River, and together they form North America’s longest river system, flowing over 3,900 miles. Their varied landscape includes forests, uplands, marshes, and sandy beaches. This creates habitats for abundant species of birds, fish, and mammals. 

From approximately the fourth millennium BCE onwards, Choctaw, Chickasaw, Sioux and other Indigenous groups used the river for fresh water and fish. European explorers traveled the Mississippi to reach the interior and northern regions of the U.S. Today, the Mississippi is a hub for tourism and home to natural and cultural sites such as Great River Bluffs State Park, Delta Blues Museum, and Mark Twain Boyhood Home. A cruise onboard an authentic Mississippi paddle wheel gives passengers the chance to experience the golden age of steamboating.

3. Yangtze River – China (3,915 Miles)

The world’s third-longest river and longest to flow within a single country, the Yangtze River loosely marks the division between north and south China. This magnificent waterway — which begins in the Tibetan Plateau and flows east to the East China Sea — has about 700 tributaries, and its basin occupies around one-fifth of China’s total land area. 

Like the Yellow River, the Yangtze is also a cradle of Chinese civilization. It has given birth to significant cultures such as the Hemudu and Chu. Chongqing, Nanjing, Shanghai, and other major cities sit on the banks of the river. It’s also home to varied wildlife, including the Chinese giant salamander, golden monkey, and red panda. A popular tourist cruise between Chongqing and Yichang sails through the spectacular Three Gorges region. 

2. Amazon River – South America (4,000 Miles)

Though it has been the source of much debate over the years, most scientists agree that the Amazon River is the second-longest river on the planet, flowing for about 4,000 miles. The Amazon is also the largest in terms of width and volume. On its route from the Peruvian Andes to Brazil’s Atlantic coastline, it weaves through the Amazon rainforest, which is among the world’s most important ecosystems. In fact, the river is so large that it carries an estimated 20% of all river water on Earth’s surface that enters the ocean. 

The Amazon River basin extends into Bolivia, Brazil, Colombia, Ecuador, Peru, and Venezuela. It shelters around 350 Indigenous groups, several of which live in complete isolation. The river is also rich in wildlife, namely the Amazon river dolphin, Amazonian manatee, and 60 species of piranha. Cruises departing from Iquitos, Peru, and Manaos, Brazil, offer an up-close and fascinating glimpse of the river’s varied peoples, flora, and fauna. 

1. Nile River – Northeast Africa (4,100 Miles)

Connecting the lands of ancient civilizations with modern cities, the Nile flows longer than any other river on Earth. Originating from Lake Victoria (in Kenya, Tanzania, and Uganda), the Nile flows north for over 4,000 miles to the Mediterranean Sea in northern Egypt. In total, it travels through or along the border of 10 African countries. 

Aside from being a lifeline of water and natural resources to millions of people, the Nile carries the footprint of Egyptian history. Ancient Egyptians created irrigation systems to take advantage of the river’s annual flooding to cultivate beans, cotton, wheat, and more. They used the river as a highway to transport these goods and people. Along its banks, Ancient Egyptians built remarkable settlements such Aswan, Cairo, and Luxor, which are still decorated today with pyramids, temples, and tombs. 

Travelers often look forward to fall as a time to take advantage of cooler temperatures and a colorful change of scenery. In autumn, many towns in the U.S. go through a fleeting transformation, as leaves on trees start to crinkle up and turn from green to fiery reds, oranges, and yellows. This is a leaf peeper’s favorite time of year — a time when hunting down the most spectacular fall foliage becomes a full-blown sport. Take a peak at 11 of the best leaf peeping locations around the U.S.

Asheville, North Carolina

Asheville is one of the best places in the Southeast to catch fall colors, thanks to its high number of tree species, diverse elevations, and unique mountain microclimates. All of that comes together to give the area one of the country’s longest leaf-peeping seasons, which typically lasts from late September to early November. The Asheville area’s mix of trees (over 140 native species) blankets the Blue Mountains in vivid yellow, orange, red, purple, pink, and brown hues. For the best light, head out at sunrise or sunset and enjoy a leisurely drive on the Blue Ridge Parkway, stopping at the many overlooks and hiking trails, including Mount Mitchell — the highest peak east of the Mississippi River.

Conway, New Hampshire

The small town of Conway charms any time of the year, with its quaint New England architecture, quirky boutiques, and cozy coffee shops. Come fall, however, Conway becomes one of New England’s top leaf-peeping destinations. Located on the edge of the White Mountains National Forest, the town is surrounded by rugged peaks and rolling foothills that glow with fiery reds, oranges, yellows, and golds from late September into mid-October.

To best admire them, take the Kancamagus Highway (Route 112), which winds for 34.5 miles through the heart of the White Mountains. Around every bend, brilliant foliage steals the show, with plenty of pull-offs and trails along the route where you can stop, stretch your legs, and take in the glorious colors. 

Sedona, Arizona

Fall foliage isn’t just reserved for the East Coast — many regions along the West Coast and in the Southwest put on a spectacular display as well. In particular, the dramatic red-rock landscapes of Sedona, Arizona, make the vibrant colors even more striking come autumn. Peak foliage season runs from late September to late October, but the season extends into November and even December at lower elevations. 

One of the most beloved spots to take in the colors is Red Rock Crossing, where golden cottonwoods along Oak Creek glow against the fiery backdrop of Cathedral Rock, drawing photographers from all over the country. For an easy, relaxing way to take in the scenery, cruise the Oak Creek Canyon Scenic Drive, which stretches for 30 miles between Seonda and Flagstaff. Must-stop spots include Midgley Bridge and Slide Rock State Park.

Stowe, Vermont

Stowe packs a big punch when it comes to outdoor pursuits — and fall is when the tiny town of 5,000 truly comes alive. In autumn, the abundance of sugar maple trees surrounding this popular northern Vermont ski area put on a spectacular color show. Visitors can enjoy it all while hiking up Elmore Mountain or Stowe Pinnacle, taking a scenic drive along the backcountry roads, or venturing out into the Waterbury Reservoir on a private boat cruise. In Stowe, the best time for fall foliage viewing starts in early September and runs through late October.

Jackson Hole, Wyoming

The scenery around Jackson Hole is nothing short of breathtaking, and autumn takes it to a whole new level. Brilliant gold, orange, and red leaves pop against the majestic backdrop of the Teton Range, making late September to mid-October a truly magical time to visit this small mountain town.

Scenic drives through Grand Teton National Park — especially along the Snake River — show off some of the best fall colors. Hiking is another favorite pastime for leaf-peepers, with trails like Taggart Lake and the Jenny Lake Loop offering unique views of the foliage reflecting in the water. Fall in Jackson Hole is gorgeous but fleeting, with snow often arriving by November, so plan to visit in early October to catch peak leaf-peeping season.

Bar Harbor, Maine

As the gateway to stunning Acadia National Park, the small coastal town of Bar Harbor is already on many tourists’ radars. Peak tourist season is July and August, but it’s well-worth holding off a few months to experience a slice of Maine magic in autumn. Hiking and biking the carriage trails within the park is often the best way to see the vibrant colors of fall, or you could embark on a kayak tour or whale watching excursion along Maine’s rugged coast. Don’t delay too long, though —  prime foliage season is short-lived in Maine, typically kicking into gear in the last week of September and lasting into the first or second week of October.

Catskills Mountains, New York

Upstate New York is known for its pristine mountains, crystalline waterfalls and rivers, and a rich profusion of trees. As you might guess, when summer fades into fall, the Catskills Mountains — located about midway between New York City and Albany — turn into a leaf peeper’s dream.

Hiking and taking scenic drives are the most popular way to see the fiery fall leaves, but visitors who prefer a more unique experience can hop aboard the Delaware & Ulster Railroad to cruise through the mountain landscape aboard a vintage train. Be sure to also visit Vernooy Kill Falls to see one of the area’s most picturesque waterfalls adorned in autumn colors. Leaf-peeping season in the Catskills usually peaks during the first few weeks in October. 

Columbia River Gorge, Oregon and Washington

New England is stacked with idyllic leaf-peeping destinations, but discounting the West Coast would be a mistake. Columbia River Gorge is stunning in any season, but the fall foliage bloom is nothing short of spectacular. Running along the boundary of Oregon and Washington, the river canyon stretches 80 miles long and reaches 4,000 feet deep in places, creating a breathtaking natural landscape that draws visitors from across the nation. 

There’s plenty of fall foliage to admire on a hike through the rocky cliffs and Cascade Mountains surrounding the gorge, but you can also hop onto Highway 30 and soak up the spectacular views on the drive between Rowena and Mosier. Or cruise down the Historic Columbia River Highway, aptly dubbed “the King of Roads” for its stunning scenery. Time your visit for late September to mid-October for peak leaf peeping.

Munising, Michigan

Leaf peeping usually conjures images of dense forests flush with color. What makes Munising special is the burst of fall color along the waterscape of the Pictured Rocks National Lakeshore, located on Michigan’s Upper Peninsula. Visitors can take to the 100 or so miles of hiking trails along Lake Superior’s shore, mountain bike or ATV through an extensive trail system, hike the famous Chapel Basin Loop, or glide out onto the chilly waters of the lake on a boat tour. No matter how you decide to see the foliage, the fiery trees that top the soaring lakeside cliffs are a sight to behold. Plan your visit during the first two to three weeks of October to catch the most colorful show. 

The Berkshires, Massachusetts

Spanning western Massachusetts to northern Connecticut along the New York border, the Berkshires are famous for their natural beauty — especially in fall. Starting in late September, the dense forests of this mountainous region turn into vibrant carpets of gold, red, and orange, and there are plenty of ways to take it all in.

The 63-mile-long Mohawk Trail (Route 2) and the 35-mile Jacob’s Ladder Scenic Byway (Route 20) are both great choices, with many pull-offs, viewpoints, and quirky roadside shops. Hiking is another popular way to catch the colors. Beginners and families can enjoy the easy, paved Ashuwillticook Rail Trail, while experienced hikers can tackle Mount Greylock for panoramic views that stretch for miles.  

Breckenridge, Colorado

Famed for its hiking, biking, and skiing trails that criss-cross the Rocky Mountains, Breckenridge is a nature lover’s dream. When the temperatures start to dip in autumn, though, the area’s beauty is showcased in a whole new way. Visitors can start wandering around Breckenridge’s charming downtown, set against a picturesque mountain backdrop, and then venture off on one of the 100-plus hiking trails nearby.

Aspen Alley is a popular hike in fall, or opt for a scenic drive along Boreas Pass Road. After a day on the trail, take a load off at a fall festival or event in town. Just be sure to consider Breckenridge’s location prior to planning your trip — due to the high elevation (9,600 feet above sea level), leaves start to change here in early September.