From an island infested with snakes to a vault holding a very special secret recipe, check out a few of the many dangerous, mysterious, or otherwise forbidden places are off-limits to the general public, adapted from an episode of The List Show on YouTube.

1. Ilha da Queimada Grande

Ilha da Queimada Grande, or “Snake Island,” is an island off the coast of Brazil that’s home to a rare and incredibly deadly species of snake called the golden lancehead. According to some estimates, there are one to five snakes for every square meter of land on the 43-hectare island. (A population survey of the area indicated that those numbers are probably an exaggeration, but even so, there are definitely a lot of snakes on the island.)

The vipers mainly eat the migratory birds that visit the island, and they’ve evolved a venomous bite strong enough to take down their prey before they can fly away. The snakes are so dangerous that the Brazilian government has forbidden people from visiting the area. Rare exceptions are made, mostly for scientists studying the species, but they have to be accompanied by a doctor—just in case.

2. Lascaux Cave

The International Center of Parietal Art at the foot of the hill of Lascaux in Montignac, France, features an exact replica of the original caves.Patrick Aventurier/Getty Images

Though not many people are eager to go to Snake Island, you may be sad to hear that you can’t visit Lascaux Cave in France. Discovered in 1940, the cavern contains some of the most iconic cave paintings ever studied. The sketches of horses, deer, and other animals date back to the Upper Paleolithic period, 15,000 to 17,000 years ago. The cave opened to the public in 1948 and closed permanently after just 15 years. The artificial lights installed there had been promoting algae growth on the cave walls and causing the painting’s colors to fade. (The microbes humans brought in with them apparently weren’t helping, either.) Lascaux Cave is now off-limits to visitors, but archaeology fans can check out a perfect replica of the site located right next door.

3. Ise Grand Shrine

The first iteration of this Shinto shrine in Japan was constructed around 2000 years ago, and since the late 7th century, it’s been torn down and rebuilt every two decades. This tradition symbolizes the Shinto concepts of death and rebirth, but it has practical purposes as well. Reconstructing the shrine about once a generation helps keep the traditional shinmei-zukuri architectural style alive. Wood also has a shorter lifespan than most building materials, so demolishing the shrine before it can rot is a way to beat nature at its own game.

When Ise Grand is rebuilt, every detail of the ornate design has to be replicated, making it one of the most expensive structures in the country. Reconstructing Ise Grand and its hundreds of secondary shrines costs the Japanese government $500 million each time, and most of that cost and effort ends up going unseen: While tourists can view it from the outside, the inside of the shrine is only accessible to the highest priestesses or priests.

4. The Svalbard Global Seed Vault

The entrance to the Svalbard Global Seed Vault in Longyearbyen, Norway, taken during a heatwave in July 2020.Sean Gallup/Getty Images

The Svalbard Global Seed Vault is located on the remote Arctic island of Spitsbergen in Norway. The 11,000-square-foot space houses more than 1 million seed samples native to places around the world. The vault acts as a sort of back-up drive of the world’s crops, preserving specimens in a safe place in case a disaster ever wipes them out in their natural environment. The facility is built to protect its contents from unwanted visitors along with everything else. It’s deep enough underground and high enough above sea level to withstand earthquakes, ocean rise, and nuclear attacks.

5. The Vatican's Secret Archives

Millions of people visit the Vatican in Rome each year, but there's at least one area in the tiny sovereign state that's strictly off-limits. Established in 1612, the Vatican Apostolic Archive (formerly the Vatican’s Secret Archives) contains the personal documents of all the popes. The archives were completely classified until 1881, when Pope Leo XIII gave Catholic scholars special access to the materials. Today, the collection remains closed to everyone but certain accredited scholars. Researchers who are allowed inside can request up to five files a day, but they have to know exactly what they want because browsing is forbidden. Who knows what we’d find out if they let Tom Hanks run loose in there for a few hours.

6. Coca-Cola’s Vault

The entrance to the Coca-Cola Museum in Atlanta, Georgia. Simon Bruty/Allsport

The World of Coca-Cola Museum in Atlanta, Georgia, is the site of a multi-million dollar vault that’s said to safe-guard Coke’s secret formula. Tourists can see it from the outside, but the interior is strictly limited to top executives. Though the vault itself is likely a publicity stunt, the formula is apparently a real, handwritten recipe that’s been in the company’s possession since at least the 1920s. It sat in a safe deposit box at an Atlanta bank for decades before moving to its current home at the World of Coca-Cola in 2011. Despite all that trouble, Coke’s secret formula may not be much of a secret at all. That same year, This American Life shared a recipe for Coke that had allegedly been passed down from a mysterious pharmacist. Coca-Cola, of course, denies that this formula is the same one they have locked away.

7. Uluru (Formerly Ayers Rock)

One of the world’s most famous forbidden places hasn't been forbidden for that long. In October 2019, Uluru, or the Australian landmark formerly known as Ayers Rock, closed to the public. Climbers had been trekking to the outback for decades just to scale the iconic rock formation. But long before it was a tourist attraction, Uluru was a sacred place to Indigenous groups. Following petitions from the Anangu people, the board of the Uluru-Kata Tjuta National Park finally announced plans in 2017 to ban hikers from the site for good. (You can still visit the area, but climbing the rock is forbidden.) In case that isn’t enough to keep people away, there are also rumors of a curse that targets disrespectful tourists. Visitors who have collected rocks from Uluru have reported streaks of bad luck, and enough of the cursed keepsakes have been mailed back to park rangers to earn them the nickname “sorry rocks.”

8. The Island of Surtsey

An aerial view of Surtsey.Bruce McAdam, Wikimedia Commons // CC by SA 2.0

In the 1960s, an undersea volcanic eruption created a brand-new island off the coast of Iceland. It’s not every day that scientists get to study an island from the moment it emerges, so they decided to make the most of the opportunity. The island, named Surtsey, has become a case study for how ecosystems develop without any interference from humans. (Other than the ideally noninterventionist scientists who study the island, that is.) Some of the lifeforms that have found their way to Surtsey include molds, fungi, at least 89 bird species, and, supposedly, one plucky tomato plant.

In 1969, an Icelandic scientist named Ágúst Bjarnason was asked to make a trip to Surtsey to identify a mysterious plant, which he identified as a tomato. Bjarnason looked into the situation a bit further; as he later recalled, “Someone had done their business … and this beautiful tomato plant … had grown out of the feces.”

Fun fact: In Iceland, a euphemism for going no. 2, which Bjarnason used in relating his tale, can be roughly translated as “playing chess with the pope.”

9. Heard Island, the Home of Mawson Peak

Some islands are off-limits for the public’s own good. Heard Island in Antarctica is an Australian territory, and it’s one of the more dangerous places on Earth. A 9000-foot-tall volcano on the island named Mawson Peak has been active since at least 2000, and wind speeds there average around 20 mph. While you could apply for a permit to visit the island, getting there wouldn’t be easy: Heard Island is at least a two-week’s journey by boat from Australia.

10. Montserrat’s Designated Exclusion Zone

A warning sign at the entrance to Montserrat's exclusion zone.Christopher Pillitz/Exclusive by Getty Images

Thankfully no one was around when Mawson Peak became active, but that wasn’t the case on the Caribbean island of Montserrat in the 1990s. When the Soufrière Hills volcano awoke from dormancy in 1995, the nearby town of Plymouth was evacuated and eventually abandoned altogether as eruptions continued. Ash consumed the town, turning it in a modern-day Pompeii. While the volcano is not as destructive as it was a few decades ago, there’s a chance it could erupt again, which means more than half the island is still a designated exclusion zone.

11. Chernobyl Exclusion Zone

Following the meltdown at the Chernobyl Nuclear Power Plant in Ukraine in 1986, a 18-mile radius exclusion zone was established around the site. Though it's still against the law to live there, you can take a day trip with a licensed guide. Most of the exclusion zone is now open to tourists, including the infamous Reactor 4 control room where the disaster took place. You'll need a hazmat suit to enter the control room, but you can get away with long-sleeved clothing outside the power plant.

12. Area 51

The gate of Area 51.Tim1337, Wikimedia Commons // CC by SA 3.0

Area 51 is famously off-limits to the public. The government refused to acknowledge its existence until 2013, when they finally admitted there was indeed a “flight testing facility” in the Nevada desert. Its restricted status didn’t stop people from planning a raid on Area 51 in September 2019. Though more than 2 million people RSVP’d to the “Storm Area 51” event on Facebook, only a few dozen showed up at the gates at the appointed time. The would-be stormers were quickly forced to leave by authorities, meaning the truth is still out there.

13. North Korea’s Room 39

North Korea's version of Area 51 is Room 39, but instead of military secrets, it's said to hide things like black market Viagra. The name refers to the secret department as a whole, but it’s also believed to be the name of a real office in the Workers Party building in the North Korean capital of Pyongyang. According to some defectors, it keeps foreign cash flowing into the pockets of elite officials. Illegal activities coming out of Room 39, such as counterfeiting, insurance scams, and drug production, along with some legal endeavors, are estimated to make the country between $500 million and $2 billion USD. Of course, the country’s notorious secrecy makes all of this hard to confirm.

14. The Island of Poveglia

A dormitory in the psychiatric ward of the abandoned Hospital of Poveglia.Marco Secchi/Getty Images

Poveglia in Italy is deserted today, but it’s been said that over the years, 160,000 people have lived, and died, there. The Venetian island became a quarantine station in 1793, and for two decades it was a place for potential victims of the bubonic plague. So many people died there that up to 50 percent of the island’s soil is said to contain human remains. The quarantine station closed in 1814, but Poveglia’s dark history didn’t end there. A mental hospital opened at the site in the 1920s, and it quickly developed a reputation for its inhumane treatment of patients. The hospital closed after a few decades, and today the overgrown island is largely closed off to visitors—except for the occasional ghost hunters.

15. North Brother Island

New York City is also home to an abandoned quarantine island. In the late 19th century, North Brother Island on the East River became the site of a hospital for patients with contagious diseases. Its most famous patient was Typhoid Mary, America’s first known asymptomatic carrier of the bacterium responsible for typhoid fever. Mary Mallon unknowingly got dozens of people sick while working as a cook in the early 1900s. She spent three years quarantined on North Brother Island after the first outbreak she caused, and when she was eventually released, she went back to cooking and infected even more people. Mary was sent back to the hospital against her will in 1915 and lived there until her death in 1938. The deserted island now serves a much happier purpose as a bird sanctuary. It’s inaccessible to the general public, but the city does make some exceptions for visitors with “compelling academic and scientific” reasons to visit.

16. Heart Reef

An aerial view of Heart Reef.kokkai/iStock via Getty Images Plus

Heart Reef, which is part of Australia’s Great Barrier Reef, is a serious candidate for “world’s most photogenic location.” As the name suggests, the reef is shaped like a heart, and it’s been the subject of countless Instagram posts and tourism campaigns. It may be iconic, but you can’t actually see the landmark up close. Divers and snorkelers have been banned from the spot to protect it from damage. So if you want to snap that perfect vacation pic without hurting a delicate ecosystem, you’ll need to pay for a helicopter ride.

17. The Ethiopian Church That Claims to Hold the Ark of the Covenant

Ethiopia claims that it’s home to the Ark of the Covenant. It’s kept in a church in the city of Aksum that’s so closely guarded, even Indiana Jones would have trouble getting in. According to legend, the monks who guard the treasure have been trained to kill with their bare hands. By some accounts, only the monk who is designated as guardian is able to see the Ark, and after assuming his role he isn’t allowed to leave the church grounds for the remainder of his life. The secrecy and potential myth-making means that archaeologists haven’t been able to confirm the Ark’s legitimacy. A British historian who claimed to have seen it during World War II said that it’s actually a medieval-era replica.

18. Maya Bay

If you've seen The Beach, you're familiar with Maya Bay.MosayMay/iStock via Getty Images Plus

Maya Bay in Thailand was also shut down to protect its environment from visitors, but the closure is only temporary. Following the release of the Leonardo DiCaprio movie The Beach in 2000, Maya Bay became a popular tourist destination. The beach was attracting millions of people a year at its peak, which wiped out a lot of the coral native to the area. Thailand made the decision to close Maya Bay in June 2018 to give the ecosystem a chance to recover. The plan is to reopen the beach with tighter restrictions at some point (potentially at some point in 2021), but as of now it remains a forbidden destination.