Optical illusions occur when the human eye perceives things differently than they actually are. But they aren’t just an abstract concept — there are plenty of examples found in nature. From a surreal salt flat that’s almost as big as the state of Connecticut to a mind-boggling waterfall seemingly made from fire, these are five of the most unreal looking optical illusions you can see in real life.

Firefall – Yosemite National Park, California

For most of the year, Horsetail Fall is just a small waterfall on the famous El Capitan rock formation in Yosemite National Park. However, something magical happens to the waterfall at sunset towards the end of February. During this time, the waterfall looks as if it’s on fire, which has earned it the nickname “Firefall.” The reflection of the sun hitting the falling water at just the right angle is what makes it look like lava pouring over the edge of the mountain. 

It’s not only the time of day and the time of year that you’ll need to get right, however. There is an element of luck if you want to see this optical illusion in its full glory. You’ll need Mother Nature to cooperate — if there is even a little bit of cloud cover, it can ruin your chances of seeing the epic “Firefall.” But visitors remain undaunted: The optical illusion is now so popular that it has forced the National Park Service to implement new rules. There are now limited areas for viewing in an effort to reduce traffic jams. 

Rakotzbrücke – Germany

Rakotzbrücke is known to many as the “Devil’s Bridge,” but don’t let that moniker deter you. The forest-shrouded, 19th-century stone bridge and its reflection on the water below creates one of the most tranquil scenes in all of Europe. Located in Gablenz, Germany — about a two-hour drive from Berlin — the delicate footbridge features thin spires at both ends, which arch up from the ground in a near-perfect semicircle. But most park-goers are hoping to visit on a clear day with calm winds, when they can witness the incredible illusion of a full circle made with the reflective lakewater below. 

The bridge was commissioned in 1860 by a local knight, Friedrich Hermann Rötschke, as the centerpiece of the Azalea and Rhododendron Park Kromlau, a 200-acre park he created and financed. Rakotzbrücke is not the only Devil’s Bridge in Europe, either — the name was given to several bridges with local legends behind them. In the case of Rakotzbrücke, it’s said that the bridge’s designer consulted with the devil when coming up with its gravity-defying shape. Though crossing the bridge is no longer permitted to preserve the structure, thousands still pay a visit each year to capture a photograph of this mythical wonder.

Salar de Uyuni – Bolivia

The largest salt flat in the world covers more than 4,000 square miles of Bolivia’s windswept western landscape — which, incredibly, is almost the size of the state of Connecticut. Resembling a shattered slab of ice, Salar de Uyuni (Uyuni Salt Flat) formed when a lake dried up between 10,000 and 25,000 years ago. The Indigenous Aymara peoples have long gathered cooking salt from here, and today, the sprawling natural wonder, located 12,000 feet above sea level, serves as a major source of salt for the entire country. Uyuni contains vast amounts of untapped lithium beneath the surface, the result of prehistoric volcanic eruptions. 

It’s also increasingly popular with visitors, though it can be challenging to get to. Many of them come to experience the Palacio de Sal (Salt Palace), the world’s first salt hotel. Located on the edge of the salt flat, the lodging is built entirely of salt. The best time to appreciate the salt flat in all its glory is usually between December and April, the season when Salar de Uyuni collects rainwater to create an astonishing mirrored reflection on its surface. 

Underwater Waterfall – Mauritius

A tropical island nation about 700 miles east of Madagascar, Mauritius is geographically isolated enough to merit its own time zone — and a trove of geological wonders found nowhere else. Within the past decade, mineral samples estimated to be 3 billion years old have been extracted from underneath the island’s beaches. Researchers believe that an ancient, lost continent called Mauritia compressed and sunk into the Indian Ocean, a disruption partly responsible for the volcano that generated this island. 

Mauritius sits on an ocean shelf sprawling about 500 feet below sea level — and there’s a steep 2.5-mile drop to the ocean floor from the shelf’s edge. From above, you’ll see what resembles an underwater waterfall off the island’s southwest coast. In reality, currents are forcing sand from the beaches and ocean shelf to greater depths. Although there’s technically no waterfall, the churning sediment creates a glistening medley of blues, greens, and whites. The best way to experience the phenomenon is on one of the many helicopter tours that fly above the climactic seascape, and also provide a bird’s-eye view of nearby Black River Gorges National Park and Le Morne Brabant Mountain. 

Sossusvlei – Namibia

Southwestern Namibia is home to some of the world’s tallest sand dunes — windswept, rust-colored giants that tower as high as 1,200 feet above the scorched earth of the Namib Desert. The dunes are part of the planet’s oldest desert — estimated to date back 55 million years — and wrap around a 12,000-square-mile salt and clay pan known as Sossusvlei. Translating to “dead-end marsh,” Sossusvlei sprawls at the furthest reaches of the Tsauchab River, where the dunes come together to stop its flow just 37 miles short of the Atlantic Ocean.

Part of what makes the view so remarkable is that the empty pan accentuates the height of the sand dunes surrounding it. Area winds blow from every direction, causing the undulating dunes to shift and erase ostrich, springbok, and hyena footprints, while concealing thirsty camel thorn tree roots that extend hundreds of feet below ground. The most popular dune to visit is Dune 45, which stands roughly 278 feet tall and can be climbed in an hour, but an unforgettable way to take in the incredible scenery is a sunrise hot air balloon ride.   

Given their location, lakeside towns are naturally peaceful and scenic, and it’s no surprise that they often double as popular vacation spots. Indeed, with their recreational activities, thriving artisan communities, access to wildlife, and overall tranquil vibes, it’s difficult to find the negative side of a lakeside retreat. Nonetheless, certain lake towns stand out from the pack. Here are six of the most beautiful lake towns in the U.S. to visit this summer.

Saugatuck, Michigan

Michigan lays claim to four of the five Great Lakes — Erie, Superior, Huron, and Michigan — plus around 11,000 other lakes. All that to say, if it’s a pretty lake town you seek, the Mitten State won’t let you down. Part of Michigan’s “Art Coast,” Saugatuck is an especially quaint lake town that earned Midwest Living’s Best Beach Town award in 2021. 

Saugatuck brims with beauty both natural and human-made, from the strip of art galleries and restaurants in old Victorian buildings that line the town’s historic main drag to the golden sandy shores of Oval Beach on Lake Michigan. Away from the water, Saugatuck offers a host of nature activities in Saugatuck Dunes State Park, such as swimming, wildlife viewing, and miles of pretty hiking trails that traverse the coastal dunes and adjacent forest. 

Wolfeboro, New Hampshire

The natural beauty of New England is no secret, and the small town of Wolfeboro showcases it spectacularly. Wolfeboro claims the crown of the “Oldest Summer Resort Town in America,” with a history dating to when the colonial governor of New Hampshire built his summer home on Lake Wentworth in 1763. A testament to Wolfeboro’s timeless appeal is the annual seasonal population increase — from around 6,500 permanent residents to a whopping 25,000 in the summer. 

On the opposite side of town is Lake Winnipesaukee, the biggest lake in New Hampshire. Visitors flock to this 72-square-mile body of water to swim off one of the many beaches, boat to one of the hundreds of islands, explore craggy coves, or embark on one of the many epic hikes in the foothills of the famous White Mountains that encompass the lake.  

Rangeley, Maine

Located roughly 2.5 hours north of Portland, Rangeley is a backwoods country town flush with the rugged beauty Maine is known for. Rangeley’s 55 square miles are sparsely populated with around 1,200 residents, but the town’s location on its namesake lake has been drawing visitors to western Maine for decades. Rangeley Lake is a popular fishing hub for trout and salmon in the summer and a base for many avid skiers and snowboarders seeking fresh powder at Saddleback Mountain in the winter. 

If you’re not into casting a line or extreme downhill sports, there’s still plenty to pique your interest. Waterfalls beckon to be discovered, and kayak, canoe, and boat rentals are available to explore the lake. Meanwhile, wildlife such as loons and bald eagles abound, and the hiking is some of the best Maine has to offer.

Lakeway, Texas

A welcome retreat for Austinites during the hot summer months, Lakeway is located 40 minutes northwest of the capital on the shores of Lake Travis. Lakeway was once a sleepy town that attracted retirees and second-home owners, but the lake’s golden sands, warm waters, and verdant surroundings have caught the attention of many more tourists in recent years. Boat tours, party coves, and plenty of amenities encircle the lake, but if you’re seeking peace and quiet, Lakeway offers cottage rentals, access to Lake Travis parks, and a welcoming, laid-back atmosphere.

Breaux Bridge, Louisiana

If you’re looking for an introduction to Cajun country, look no further than Breaux Bridge. Located 5 miles from Lake Martin, the town of approximately 7,500 is known as the “Crawfish Capital of the World.” Breaux Bridge claims to have invented the crawfish etouffee and continues to host an annual crawfish festival. Needless to say, sampling crawfish while in town is a must. 

Breaux Bridge is also a great jumping-off point to explore the surrounding bayou landscape. Swamp tours on Lake Martin and Atchafalaya Basin offer excellent opportunities for spotting wildlife including heron, barred owls, turtles, osprey, and alligators. Meanwhile, you can admire the majestic cypress trees with moss-draped branches that grow straight out of the lake floor. In addition to water activities, nearby hiking and walking trails — such as the Lake Martin Loop Trail and the Cypress Island Nature Trail — are tranquil alternatives to soak up the beauty of the bayou.

Eureka Springs, Arkansas

Eureka Springs, a small town of around 2,200 people, may seem like a blip on the map, but it has long attracted droves of visitors in the summer months. Eureka Springs is nestled in the Ozark Mountains and located within a few miles of Beaver Lake and Lake Leatherwood. Both of these lakes offer visitors cottage or campsite rentals and a plethora of recreational activities such as kayaking, fishing, and hiking. 

However, the main draw here is the access to multiple natural mineral springs that encircle Eureka Springs and were discovered in the 19th century. Within walking distance of the town center, you’ll find bathhouses and spas supplied with the natural spring water, but the most popular is Palace Hotel and Bath House, the only one of the town’s former historic bathhouses still in use today. Whether you choose to spend time on the lake or in the healing mineral waters, a visit to Eureka Springs is a sure bet for a memorable summer getaway. 

By definition, an island is a body of land that’s entirely surrounded by water. Islands are typically accessible by aircraft or boat, but around the world there are some islands that are technically only islands at high tide. When the water levels are low, they become connected to the mainland by sandbars, natural pathways, or causeways. So, lace up your favorite walking shoes, wait for low tide, and walk to these seven fascinating islands. (Just don’t get stuck when the water starts to roll in again.)

Mont-Saint-Michel – France

Mont-Saint-Michel rises like a floating Disney castle out of a bay shared by the French regions of Normandy and Brittany. This UNESCO World Heritage Site first caught the eye of pilgrims in the eighth century, when St. Aubert was divinely guided to build a hilltop church. The Duchy of Normandy and French royals later funded the construction of the island’s spectacular Benedictine abbey. 

Cars can drive continuously over a causeway, but the more adventurous way to arrive is to walk across the bay at low tide. Setting foot on the island is akin to stepping back in time to a medieval village. Visitors can stroll the zigzagging alleyways to discover taverns, restaurants, and gift shops — or even stay overnight at one of the island’s handful of hotels and guesthouses.

Bar Island – Maine

Located off the coast of charming Bar Harbor, Bar Island is part of Acadia National Park, the first national park established east of the Mississippi River in 1919. Twice a day, a short strip of sand, rocks, and pebbles called Land Bridge provides access to the island, which was once inhabited by farmers before it became part of the national park. 

The best time to avoid getting your feet wet is about an hour and a half before or after low tide. Several plant and animal species, including starfish, appear in natural tide pools on the bridge. On the island itself, the Bar Island Trail is a 1.9-mile out-and-back route that traverses through serene forest and wildflower meadows. Keep an eye out for the remains of old buildings and enjoy views back toward Bar Harbor and over Frenchman Bay. It’s a nine-hour wait between tides, so pay attention to the time to avoid getting stranded. 

Brough of Birsay – Scotland

Part of Scotland’s remote Orkney Islands, Brough of Birsay was home to Pictish and Norse settlements from around 600 to 1200 CE. A causeway provides access to this picturesque island from the village of Birsay and the chance to explore the 10th-century ruins of a Norse hamlet. 

A replica of a carved stone on the island shows four Pictish symbols, including a crescent and an eagle. (The original is located at the National Museum of Scotland.) Also of interest are the remains of the Romanesque-style St. Peter’s Chapel, which dates to the 12th century. A whitewashed lighthouse stands solemnly on one side of the island, and all around are views of deep blue Atlantic waters and craggy cliffs, where guillemots, puffins, and razorbills nest. 

Haji Ali Dargah – India

According to legend, after the Muslim saint Pir Haji Ali Shah Bukhari died on a pilgrimage to Mecca, his casket floated back to a rocky islet on Mumbai’s western shoreline. To honor this miraculous event, a mosque and a dargah (tomb) were erected in the 15th century and named Haji Ali Dargah. 

Today’s structure mostly dates to the 19th century, and for much of the day it’s a glistening, fairy-tale-like scene of brilliant white domes and minarets. As the water recedes, worshippers form an orderly line across a stone causeway to pay their respects to the revered merchant and spiritual teacher. It’s worth the walk to admire intricate mirror work and mosaic decorations, in addition to the saint’s opulent marble-enclosed floating tomb. 

Holy Island of Lindisfarne – England

The Holy Island of Lindisfarne sits on the faraway and windswept coast of Northumberland, in northeastern England. It was here in 635 CE that St. Aidan arrived from Iona and established a monastery, which later became home to the admired saints Cuthbert and Oswald, before vikings plundered the island in the eighth century. 

At low tide, the 3-mile-long Pilgrims Way reveals itself to create a scenic walk to the island. Visitors can stroll in the footsteps of monks at Lindisfarne Priory and explore the Tudor-era Lindisfarne Castle. A community of fewer than 200 people lives here permanently, and you can experience village life at the island’s cafés, pubs, specialty shops, and guesthouses. Holy Island is the last stop on St. Cuthbert’s Way, a 62-mile walking trail that begins in the Scottish town of Melrose. 

Ministers Islands – New Brunswick, Canada

Fascinating First Nations heritage, historic buildings, and epic hiking trails await on the 500-acre Ministers Island in Canada’s eastern New Brunswick province. This unique island is linked to the mainland by an ocean-floor gravel passage rather than a sandbar or human-made causeway. This allows for both pedestrian and vehicle access from the town of St. Andrews. First inhabited by the Passamaquoddy peoples, the island later became the summer home of Canadian railroad pioneer Sir William Van Horne from 1890 through the mid-20th century. 

Now a designated National Historic Site of Canada, the island welcomes visitors to explore the 50-room Van Horne mansion, a bathhouse, a former creamery, and other preserved buildings. A 12-mile network of hiking and biking trails cuts through dense forest and along picturesque shorelines. Late April to May and August to mid-October are great times to spot birds on their spring and fall migrations. 

St. Michael’s Mount – England

An emblematic image of the Cornish coastline, St. Michael’s Mount is steeped in history and mythology. Since the fifth century, legends have been told of a mermaid on the island guiding seafarers to safe passage. Another island tale tells of Jack the Giant Killer defeating the beast Cormoran. In the 12th century, Benedictine monks — the same ones who worked at the sister abbey on Mont-Saint-Michel — began construction of the island’s church and abbey. 

These days, a castle occupies the summit of St. Michael’s Mount and is the home of the St. Aubyn family. Below it, cafés and shops in old stone buildings overlook the harbor. To access the island, a cobblestone causeway crosses Mount’s Bay to the town of Marazion. Walking is the only way to get here in winter, but a ferry service operates during the summer months.