From vast national parks to scenic stretches of coastline, the USA is road trip heaven. But it isn’t just about the big sights and the breathtaking roads – it wouldn’t be an American road trip without the quirky stuff thrown in along the route.

From kitsch diners and open-air art installations to otherworldly natural wonders, click through this gallery to discover the best and most unusual roadside attractions across the US...

Local adobe clay, straw, thousands of gallons of donated paint and a lot of love were poured into creating Salvation Mountain, a vivid hillside monument in the Colorado Desert near Calipatria in southern California. It was created by local artist Leonard Knight, who began piecing it together in the 1980s as a symbol of his religious devotion. He regularly updated it with messages and embellishments up until his death in 2014.

New Jersey has its very own Ocean Drive, which skims along the Jersey Shore from Atlantic City to the golden beaches and retro amusement park of Cape May. En route is Wildwood, famous for its classic beach town vibes and fascinating strip of mid-century modern inns. Known as ‘Doo Wop’ motels, they burst with colourful details like plastic palm trees, dolphin motifs and original 3D signage.

Stonehenge might be shrouded in mystery but, in Nebraska, it’s all about Carhenge. This curious sculpture, off Highway 59, was created in 1987 by Jim Reinders as a tribute to his father. He used 39 old cars to replicate the original Neolithic stone circle which is in Salisbury, England, UK.

More like a city than a service area, Iowa 80 wears its status as the world’s largest truck stop with pride. It’s emblazoned across the entrance, in fact. There are eight restaurants, as well as a cinema, barbershop and even a dental surgery. And that isn’t even the most unusual thing about the place, which was established close to the town of Walcott in 1964. The display of fun vehicles, in shapes from hot dogs to boots, is the biggest draw.

A shoe-shaped house on Shoe House Road? It’s all part of the classic US road trip. The Haines Shoe House was built in 1949 by an eccentric shoe salesman (of course) originally as an advertising gimmick. It later became a holiday rental and remains one today. The 25-foot-long (8m) and 48-foot-tall (15m) boot sleeps six people and has gorgeous design details, including wall murals and stained-glass windows adorned with… shoes. The street on which it sits, just off the Lincoln Highway, was renamed in its honour.

There’s something enduringly fascinating about the stuff people lose or leave behind. That’s the premise behind the Unclaimed Baggage Center, which is filled with, well, unclaimed baggage. The centre takes in luggage left behind on domestic airlines and, if they can’t track the owners, selects items for sale. It's essentially a huge second-hand store stuffed with finds ranging from designer handbags to diving helmets. Other items are recycled or repurposed to be donated to communities in need.

Madonna Inn – named for its founders, married couple Alex and Phyllis Madonna, rather than the Queen of Pop – is a palace of pink off US 101 in central California. The 1950s hotel’s exterior resembles an intricate wedding cake crossed with a scene from The Flintstones, and the inside is even more outrageous with themed bedrooms and lipstick-pink bathrooms. The flamboyant Gold Rush Steak House (pictured) serves some of the best burgers in the area, while the relatively subdued Copper Cafe is famous for huge wedges of cake.

The most majestic waterfalls are usually reached via long hikes or long treks through forests. But this lofty beauty is right by the roadside. The upper portion of Multnomah Falls can even be viewed from the Historic Columbia River Highway. The cascade crashes from 611 feet (186m), with a stone bridge – built in 1914 – spanning its width.

The 32-mile (51km) Highway 21, known as the Enchanted Highway, is an open-air gallery of huge sculptures crafted from scrap metal. There are seven pieces in total, created by Gary Greff. They include the World’s Largest Tin Family and Geese in Flight, which is shaped like an eye (pictured). Some of the works can be seen from the I-94 but they’re at their surreal best viewed up close, looming through the windscreen.

If a giant orange by the roadside doesn’t seem strange enough, the fact that this is a burger restaurant – rather than a juice bar – makes this spot even more brilliantly bizarre. The Mammoth Orange can be found just off the road between Little Rock and Pine Bluff, and was built in 1966, inspired by a similar restaurant in Fresno, California. The hot dogs and hamburgers are highly rated.

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Drivers travelling along US Route 70 could be forgiven for thinking they’ve landed on another planet or somehow taken a wrong turn and ended up at an enormous, blazingly white beach. The alabaster dunes of White Sands National Park cover 275 square miles (712sq km), making this the world’s largest gypsum dune field. The white waves can be seen from the road, brightening the landscape between the San Andres and Sacramento mountain ranges.

Just off the US-95, this 12-foot-tall (3.7m) sculpture of a giant beagle used to double as a place to stay, but now it's just a quirky (and free) roadside attraction. The 'dog house' was handcrafted by the original owners using a chainsaw. They also created the series of sculptures, including a smaller dog and a fire hydrant, that dot the grassy grounds.

To describe the Ave Maria Grotto as intricate would be an understatement. To describe its creator, Benedictine monk Brother Joseph Zoett, as dedicated would be even more so. The park in Cullman, which opened in 1934, has 125 stone and cement structures depicting biblical passages, shrines and miniature replicas of famous religious buildings including St Peter's Basilica and Lourdes Basilica Church.

The lunar-like landscape of Bonneville Salt Flats sprawls out for 30,000 awe-inspiring acres between Utah’s Salt Lake City and Wendover, Nevada. The salt pans are blazingly white, cracking and curling in the heat, with nothing growing or living on the surface. There are several viewpoints along the I-80.

It’s hard to believe this intricate monument is the product of one man’s imagination, let alone built by one man’s hands. The elaborate, self-built stone and iron structure has been chiselled, embellished and decorated by Jim Bishop over six decades. What started as a one-bedroom stone cottage is now a 16-storey fortress with cathedral windows and a steel dragon. It’s just off Highway 165, which wiggles through central Colorado.

Pebble Beach’s 17-Mile Drive, just north of pretty Carmel on California’s Central Coast, is a road trip within a road trip, looping off the Pacific Coast Highway. This isn’t a drive to rush: there’s a must-stop pretty much every few minutes, from beaches with harbour seals to this forlorn but noble-looking cypress tree, which occupies a solitary, salt-sprayed perch on a rock jutting over the ocean.

This 55-foot-tall (17m) fellow is pretty hard to miss. In fact, the Jolly Green Giant is probably the most famous resident in the town of Blue Earth. The fibreglass statue, next to a museum filled with Jolly Green Giant memorabilia, was built by former radio station owner Paul Hedberg, who used to interview road-trippers before gifting them a tin of Green Giant veg – a nod to the area’s canning factory.

America’s oddities aren’t limited to quirky cafes and giant sculptures. Sometimes, the natural world rivals the human imagination when it comes to strangeness. Take Thor’s Well. Dubbed ‘the drainpipe of the Pacific’, it sucks in water and swirls it around before spurting it out with optimum drama. It can be viewed at a safe distance from the parking area at Cook’s Chasm, off the coast-skimming US 101.

There are two of these diners along the Overseas Highway, which soars through the Florida Keys archipelago. But it’s the original one in Key Largo, opened in 1976, that really takes the gravy-smothered biscuit when it comes to quirkiness. There are busy displays of licence plates inside and out, plus a huge neon sign in the car park. It isn’t all show, though – the cosy, long-running spot is famed for delicious local seafood and key lime pie.

The tiny ghost town of Oatman, on historic Route 66, has some unusual residents – wild donkeys, or burros. The animals, which roam the streets, were originally brought here by prospectors and set loose in the surrounding mountains when the gold mine closed in 1942. They’re so beloved – and such a part of the town’s fabric – they even feature on the welcome sign, and stores sell special ‘burro food’.

Desert oases tend to appear in the form of watery pools – but this looks like something springing from the imagination of a tired, hallucinogenic fan of high fashion. In some ways it is an illusion, as this Prada boutique on US Route 90 is an art installation, created in 2005 by Berlin-based artists Elmgreen and Dragset. Although it does have real merchandise on display, the bags are bottomless and all the shoes are right-footed.

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This striking series of steel statues is a prime example of art working beautifully with nature. From a distance, the 39 equine figures that make up Bleu Horses look very much like real horses – except they stay stunningly, silently still. They were created by local artist Jim Dolan to stand watch from their hillside perch off Highway 287, just north of Three Forks.

Anyone who’s ever wondered where ice cream flavours go to die could find the answer at this quirky spot attached to the Ben & Jerry’s factory in Waterbury. The Flavor Graveyard is the final resting place for retired recipes such as Tennessee Mud, Peanut Butter and Jelly, Rainforest Crunch and Turtle Soup. Tombstones have images of winged cones and poems paying homage to the doomed flavours.

A giant T-Rex beckons road-trippers to pull into Dinosaur World, off the I-65 near Mammoth Cave National Park. Or, perhaps, spurs them on to drive on by in fear. This Jurassic Park–style roadside attraction is home to around 150 dino sculptures scattered among the grounds and sometimes peeping above the trees. There’s also a small museum displaying dinosaur claws, bones and eggs.

There were once eight of these striking gas stations in North Carolina, designed to bring the Shell logo vividly to life. Now just one of the bold 1930s structures remains, in the city of Winston-Salem. The pumps no longer dispense petrol and the building has been closed since the 1950s, but it’s become a beloved curiosity in the town and has been listed on the National Register of Historic Places since 1976.

Carved out of a massive rock on US Highway 191, this unusual structure was created in the 1940s as a small alcove for the owners’ kids to sleep in. It gradually expanded into a 5,000-square-foot (464sq km) home with 14 rooms. The unusual ‘house’ is usually open for brief tours so people can see how the Christensen family once lived. Things get even more bizarre with an on-site zoo housing zebras, camels and bison.

Lucy the Elephant is rather old. The tin-and-wood structure was built in 1882, modelled after real-life elephant Jumbo who starred as the ‘Largest Elephant on Earth’ in PT Barnum’s circus. She’s also rather large, looming over the coastal city of Margate at a lofty 65 feet (20m) and weighing 90 tonnes. She once housed offices and a restaurant, the bones of which you can see on a tour of her interior (accessed by spiral stairs hidden in her hind legs).

Rhyolite, near the eastern edge of Death Valley, boomed during the Gold Rush of the early 20th century but quickly went into decline and was deserted in 1916. The remnants – including a well-preserved railroad depot, school, bank and general store – look especially eerie against the stark, shrubby, desert backdrop. A scattering of art installations, added from 1984 and including a metal model of a miner with a penguin, take the scenery to an even more bizarre level.

Officially the world’s largest catsup (or ketchup) bottle, this landmark just outside Collinsville is pure, joyful Americana. It was built in 1949 to supply water to the nearby Brooks ketchup factory and was saved from demolition in the 1990s. It’s now owned by a group of volunteers dedicated to its preservation and has been restored and added to the National Register of Historic Places.

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