If the usual cookie-cutter holiday attractions are starting to bore you, why not head off the beaten path and try a landmark imbued with history, mystery, and intrigue? If you’ve never heard of this type of travel, you’re missing out. It sounds much more ominous than it actually is, in fact, popular tourist sites, such as Ground Zero in New York, are also must-sees for fans of this type of tourism.

A quick Google search returns thousands of related results, with everything from its own website to a television series of the same name. While its name sounds bleak and unattractive, the sites themselves are dynamic and engaging, at times even uplifting.

That said, not all of the underground-style tourism attractions are treated equal—they can vary from natural wonders to ossuaries and catacombs to battle memorials, all with varying degrees of austerity. However, the idea is to push your boundaries—how uncomfortable can you get? Perhaps you’ve seen some of the popular sites, and are ready to take your black travels to the next level.

With this list, you’ve got 25 new places to explore when you’re feeling brave, or even bored with the neatly packaged tourism destinations.

25 Snake Island, Brazil- Meet This Island's Venomous Residents

There aren’t hordes of tourists lining up for the next cruise out to Brazil’s Snake Island, which is exactly what you pictured—an island swarming with snakes.

The tiny island is home to a population of over 4,000 snakes and is the only place in the world to find the golden lancehead viper, which holds the title for the world’s deadliest snake.

Even snake-lovers beware, these slithering serpents are so venomous that the Brazilian government enforces strict laws on who is given access to the island, for now, it’s restricted to research teams.

24 Pripyat, Ukraine- Chernobyl's Exclusion Zone

You might know the Ukranian city of Pripyat from the 1986 Chernobyl nuclear disaster, which left the area eerily abandoned. The city was a short-lived construction to house workers and scientists at the nuclear reactor, being inhabited from 1970-1986.

Several companies offer tours to the exclusion zone (radiation levels have been safe in recent years), where you can visit the ghostly quiet remains of what was once a bustling industrial town. A favourite attraction is the amusement park with rusted and beaten rides, including a Ferris Wheel suspended in position for an eternity.

23 Isla De Las Muñecas, Mexico- Playing On Our Fear Of Dolls

There may not be a place on earth quite as bizarre as Mexico’s Isla De LasMuñecas, or Doll Island. The small island is located south of Mexico City on the Xochimilco canals and is littered with dolls and doll parts. At first, you might feel you’ve landed on the set of a low-quality horror film, but the island was never intended to host visitors.

It’s said that the caretaker of the island, Don Julian Santana Barrera, spent 50 years hanging dolls from the trees to please the spirit of a little girl, and other visitors to the island sometimes leave their own dolls.

22 North Yungas Road, Bolivia- Where You Might Fall Off The Earth

This cliffside road in Bolivia presents a challenge for those with a fear of heights. With no barrier at the edge, expect vertigo while driving along this narrow dirt road carved haphazardly into the side of a mountain.

North Yungas Road runs from La Paz to Coroico and is the supreme route for mountain bikers, whose thrill-seeking takes them racing around these sharp corners, with little to no notice as to oncoming traffic. If mountain biking isn’t for you and you still want to experience one of the world’s most dangerous roads, you can travel between the two cities via bus.

21 Odessa Catacombs, Ukraine- More Than A Burial Site

The Odessa Catacombs aren’t your average tunnel network of bones. They make up a massive 2,500 kilometres of tunnels spidering out underneath the city of Odessa, the earliest of which date back to at least the 17th century. Limestone deposits were dug up in the 19th century to build the city, leaving the intricate tunnel system that still exists.

In times of conflict, Soviet rebels camped out in the catacombs, plotting to thwart their enemies. Later, the system became the chosen hangout for criminals and rebellious teenagers. You can explore part of the catacombs, but you’ll need a guide as they are incredibly difficult to navigate.

20 Hill Of Crosses, Lithuania- A Site Of Pilgrimage For Hundreds Of Years

Lithuania is the proud home of the Hill of Crosses, a hill that appears to randomly jut out of the otherwise flat land, crammed with thousands of crosses of varying sizes and detailed intricacy. It’s said that devoted Christians have been placing crosses here since the Middle Ages, but it’s only ever mentioned in written record beginning in the 19th century.

The Hill of Crosses is a symbol of national pride for Lithuanians and perseverance for us all, because every time an oppressor yanked out the crosses, citizens would risk their lives replanting the hill with its crosses.

19 Darvaza Gas Crater, Turkmenistan- This Pit Of Fire Has Been Burning For 50 Years

The Darvaza Gas Crater is an awe-inspiring spectacle in the Central Asian country, Turkmenistan. There are actually three craters, two filled with mud, while one flickers and burns with gas fire. They’re an effect of Soviet gas exploration, with the fire crater burning since the 1970s.

The burning crater has attracted tourists for years and has earned itself the nickname “The Door to Hell,” for good reason. You can see the fire from miles away, and at night it resembles the mouth to the centre of the earth. As it’s far into the desert, the best way to see the crater is to organise a tour.

18 Poveglia Island, Italy- Once A Plague Quarantine Site, Now Up For Auction

You don’t think of Venetian islands to have particularly intimidating histories, but just beyond the floating city lies Poveglia, a vacant island with a history of peculiar residents. It was inhabited for a millennium until the 14th century, when war drove away its people. It lay unused for four centuries, when it served as a checkpoint for trade. Things took a turn when a ship brought the plague and forced the island into a quarantine zone.

Later, it briefly housed a mental hospital and agricultural facilities before being completely abandoned. It has since been put up for auction in the hopes that it might be developed.

17 Gomantong Caves, Malaysia- Stunning, Breathtaking, Thrilling

Every traveller should visit the Gomantong Caves in Borneo once in their lives to see the towering domed ceilings and marvel at the swiftlet population. Locals climb the cave walls to retrieve the edible nests of these birds (a local delicacy), but foreigners tend to be a little more disgusted with the caves.

With a remarkable bat population comes guano, or bat excrement, and a colourful array of creatures that live in it.The cave floors are made up almost entirely of a carpet of cockroaches. If you do go, do yourself a favour and wear some waterproof boots.

16 Komodo Island, Indonesia- Beware Of Dragons

First an island of snakes, now an island of dragons. Really, the world’s largest species of “dragon”, the Komodo, makes its home on this Indonesian island. While they might look funny and innocent enough, these lizards can grow up to ten feet long and are notorious for taking down prey many times their size.

Roughly 2,000 humans make their home on the island as well, though you must be seriously brave to share an island with these (literal) monsters. Visitors occasionally come to the island, but are usually reserved to researchers and other professionals on business.

15 Madidi National Park, Bolivia- you’ll be lucky to make it out in one piece

Fantasies of the Amazon rainforest usually involve lush flora, babbling monkeys, and lazy jaguars, but the real, untamed Amazon is anything but. Try poisonous tree frogs at every corner, unlit pathways, and who knows what lurking in the rivers. Here you have Madidi National Park, in the beautiful Bolivian rainforest.

No doubt enchanting, but you’ll be lucky to make it out in one piece.

It’s a must-see for the adventurous spirit, but make sure you have every precaution handled and start your expedition with a trained guide as this is one of the most ecologically diverse areas on the planet.

14 Sedlec Ossuary, Czech Republic- This Chapel Decorates With  Bones

Now, this is a church that knows how to decorate in a pinch. Located an hour’s drive from Prague, Sedlec Ossuary is draped in ornaments made of bone, with up to 70,000 skeletons embellishing the church.

In the 13th century, holy soil from Jerusalem was scattered throughout the cemetery, making it a highly desirable burial ground. The only problem was that its popularity overcompensated for its size and in the 19th century, some of the bones were moved to a crypt, where they were artfully arranged into the décor that still remains.

13 Poenari Castle, Romania- Imagine The Real Dracula Lurking In These Walls

Although Romania’s Bran Castle is often mistaken for the home of Dracula, Poenari Castle is the ruins of the lair of Vlad the Impaler, the medieval conqueror who inspired the fictional vampire.

Dracula is based on the very real bloodlust of Vlad, and the fortress Poenari is where he carried out many of his atrocities.

Like any good vampire den, Poenari is well fortified in its hilltop position and has long fallen to ruin. To reach the castle, you must hike up the steep stairs that lead along the mountain ridge.

12 The Hellfire Club, Ireland- The Old Stomping Grounds Of Hedonistic Aristocrats

County Dublin’s Hellfire Club sounds a lot more sinister than what it really was. Atop Montpelier Hill sits an abandoned hunting lodge that was rumoured to be the site of sacrifices and black magic among Ireland’s elite.

Stories tell of ritualistic mischief held at the lodge, but the real Hellfire Club was probably a group of 18th-century aristocrats who rented the lodge to drink themselves silly. Still, a fire mysteriously burned the lodge, leaving only the outer stone shell.

You’ll find some who freely walk their dogs here on a sunny day and others who refuse to go near the lodge with its reputation.

11  Centralia, Pennsylvania- Just A Ghost Town And Its Graffiti Road

Centralia, Pennsylvania was a quaint mining town, and at its peak had a population of almost 3,000 residents along the Mine Run Railroad. That number diminished to just seven in 2013, with arrangements to turn over property to the government.

The demise of Centralia was caused by a coal mine fire in 1962, which has continued to burn ever since and slowly released gases into the town, forcing townspeople to abandon their homes.

There’s hardly anything left to the town now, but a stretch of Route 61 has been colourfully graffitied by visitors passing through.

10 Humberstone & Santa Laura, Chile- Dust-Covered Ghost Towns In The Atacama Desert

In Spanish colonised Chile, one town stands out as distinctly English—Humberstone. There’s little left to this saltpetre refinery except for a few skeletons of buildings and the old railroad tracks, but together with the neighbouring town Santa Laura, the area is a newly dedicated UNESCO World Heritage site.

In the harsh conditions of the Atacama Desert, workers toiled for 60 years producing the valuable product that was saltpetre, and in the 19th century they wouldn’t have much to cool themselves. Today, the towns rest, buried in the dust and sand of the hostile desert.

9  Castle Of Good Hope, South Africa- Doesn't Quite Live Up To Its Name

The happy, sunshine-yellow walls of the Castle of Good Hope fit right in among the palms and humid Cape Town weather. Its pentagonal outer wall makes for a star-shaped grounds, a lovely view if seen from above.

But the castle wasn’t always a cheery tourism site, in fact, it was long associated with slavery and military hardships.

It is the last remaining colonial building, and the oldest in South Africa, built in the 17th century atop an older fort. It was commissioned by the Dutch, but ultimately completed due to forced labour.

8 Leap Castle, Ireland- This Imposing Castle Is Now A Family Home

Tucked away in Ireland’s Slieve Bloom mountains is a small tower house castle, teetering off the edge of a hillside. It’s a well-preserved relic of the 16th century, and the subject of many legends in the Irish midlands.

The construction of Leap Castle was overseen by the O’Carroll clan, and it’s said that two brothers from the O’Bannons were meant to leap off the ledge, the survivor winning the rights to the castle, earning it its name and a future plagued with violence.

The current owners of the castle offer private tours of their remodeled home.

7 Medellín, Columbia- Once Dangerous, Now Buzzing With Tourists

The first thing that comes to mind when you hear the name, “Medellín,” is probably in reference to the extremely successful operation led by Escobar. You don’t picture a vibrant, modern Colombian city that’s been reborn since its days of the 1980s.

Once known as the most dangerous city in the world, Medellín now has a booming ecotourism industry and hosts an annual flower festival, as well as other seasonal festivals. It’s also got sprawling museums, all centrally located near Botero Plaza. Medellín is no longer for dangerous criminals, but youthful tourists.

6 Darién Gap, Panama- a stretch of remote jungle, where almost anything goes

If dangerous weapon-wielding groups and cartel activity don’t scare you, maybe the thousands of lethal insects and animals that roam the Darien Gap will.

Between the borders of Panama and Colombia is a stretch of remote jungle, where almost anything goes. This is the Darien Gap, and it forms a blockade along the Pan-American Highway.

Outsiders rarely attempt to travel this stretch of rainforest, but groups of hikers will occasionally venture into the jungle. Common sense tells you not to do this without extreme preparation and guidance, as it’s very easy to get lost in the untamed rainforest.