There is an island in the Bay of Bengal, roughly the size of Manhattan, where the Indian Navy maintains a permanent patrol to ensure that nobody gets within five kilometers of the shore. The island has no roads, no ports, no cell towers, no modern infrastructure of any kind. It is home to the Sentinelese—an indigenous people who have lived there in voluntary isolation for an estimated 60,000 years and have, with remarkable consistency, attempted to kill anyone who approaches. The Indian government has responded to this situation not by trying to change the Sentinelese’s mind but by making it illegal for you to try. Approaching North Sentinel Island is a criminal act under the Andaman and Nicobar Islands Protection of Aboriginal Tribes Regulation of 1956, and the Indian government has publicly stated it will not prosecute the Sentinelese for killing trespassers.
That is not a hypothetical. In 2018, American missionary John Allen Chau paid local fishermen to take him to the island, where he hoped to convert the tribe to Christianity. He made it ashore. The Sentinelese killed him with bows and arrows. In March 2025, an American YouTuber named Mykhailo Viktorovych Polyakov landed on the beach, blew a whistle, left a can of Diet Coke and a coconut as “offerings,” filmed the whole thing, and left. He was arrested two days later. Police noted he was “lucky he did not make contact otherwise he would have met the same fate.” Survival International, the NGO that advocates for uncontacted peoples, called his actions “reckless and idiotic,” which feels like an understatement for a man who traveled to the one place on Earth where the locals have a documented track record of murdering visitors so he could leave a Diet Coke on the beach and post it online.
North Sentinel Island is probably the most famous forbidden zone in the world, but it’s far from the only place where you are legally, physically, or practically unable to go. The planet is littered with them—restricted by governments, militaries, treaties, geography, or the simple fact that getting there would kill you. And the reasons a place becomes off-limits are often more interesting than the place itself.
Area 51, Nevada, United States
The Groom Lake facility in the Nevada Test and Training Range—universally known as Area 51—is the one everyone knows about and nobody knows anything about, which is the ideal combination for generating decades of conspiracy theories. What we do know: it’s a classified United States Air Force testing facility that has been used since the 1950s to develop experimental and stealth aircraft, including the U-2 spy plane, the SR-71 Blackbird, and the F-117 Nighthawk. What we don’t know: basically everything else. The airspace above it is restricted. The perimeter is monitored by motion sensors, cameras, and security personnel. Warning signs inform you that photography is prohibited and that the use of lethal force is authorized—the kind of signage that really makes you feel welcome.
The facility’s existence wasn’t officially acknowledged by the U.S. government until 2013, when the CIA released declassified documents about the U-2 program. Sixty years of officially pretending the place didn’t exist while simultaneously stationing armed guards around its perimeter is a very specific kind of bureaucratic performance art. The conspiracy theories—alien technology, reverse-engineered spacecraft, extraterrestrial autopsies—are almost certainly nonsense, but the government’s own commitment to secrecy created the perfect conditions for them to thrive. If you act like you’re hiding aliens, people are going to think you’re hiding aliens.
The Korean DMZ
The Demilitarized Zone between North and South Korea is 250 kilometers long and roughly 4 kilometers wide—a buffer strip that has been essentially untouched by human activity since 1953. It is simultaneously one of the most heavily militarized borders on Earth and one of the most pristine wildlife corridors in Asia, because it turns out that landmines and machine gun emplacements are an extremely effective conservation strategy. Red-crowned cranes, Asiatic black bears, and possibly the critically endangered Amur leopard have been spotted in the DMZ, thriving in a landscape that humans have been too afraid to enter for seventy years.
Tourists can technically visit portions of the DMZ through organized tours from the South Korean side—the Joint Security Area at Panmunjom is the one you see in photographs, where soldiers from both sides stare at each other across a concrete line. But the vast majority of the zone is completely off-limits, laced with an estimated two million landmines, and anybody wandering off the designated tour path would be facing a combination of unexploded ordnance and North Korean border guards, which is not a recreational combination.
Poveglia Island, Italy
A small island in the Venetian Lagoon, roughly halfway between Venice and Lido, Poveglia has been closed to the public since 1968 and the Italian government has repeatedly declined to sell or develop it. The island’s history is a greatest hits compilation of everything you’d want in a haunted location. In the late 1700s, it was used as a quarantine station for plague victims—ships arriving in Venice were required to stop there first, and those showing symptoms of the plague were left on the island. By some estimates, over 100,000 people died there during various plague outbreaks, and the island’s soil is reportedly so densely packed with human remains that fishermen in the lagoon occasionally pull up bones in their nets.
In 1922, the island became a psychiatric hospital, which—given the setting—feels like a creative decision that no modern institutional review board would approve. The hospital closed in 1968, and the island has been abandoned since. Italy’s government has periodically entertained bids to develop it, but access remains restricted, and anyone trying to visit without authorization faces fines. The paranormal tourism industry would very much like Poveglia to be open. The Italian government would very much like everyone to stop asking.
Svalbard Global Seed Vault, Norway
Built into the permafrost of a mountain on the island of Spitsbergen in the Svalbard archipelago—roughly 1,300 kilometers from the North Pole—the Global Seed Vault stores duplicate samples of seeds from gene banks worldwide. It’s a backup drive for agriculture. If a crop variety goes extinct due to disease, climate change, war, or catastrophic incompetence, the seeds are here. The vault holds over 1.3 million seed samples from virtually every country on Earth, stored at minus 18 degrees Celsius in a facility designed to remain frozen even if the refrigeration fails, because the permafrost provides passive cooling.
You cannot visit. The vault is not a museum. It opens a few times a year for depositors—organizations that are adding or withdrawing seeds—and for the occasional delegation of dignitaries who want a photo op in front of the world’s most famous door. The entrance, with its illuminated art installation visible against the Arctic landscape, has become one of the most photographed structures in Norway, which is remarkable for what is functionally a very cold filing cabinet.
Heard Island, Australia
A volcanic island in the southern Indian Ocean, roughly 4,000 kilometers southwest of Perth, Heard Island is technically Australian territory but might as well be on another planet. It is one of the most remote places on Earth, dominated by Big Ben—a 2,745-meter active volcano covered in glaciers—and home to colonies of penguins, seals, and seabirds that have never been habituated to humans. The island is a UNESCO World Heritage Site and access requires a permit from the Australian Antarctic Division, which is granted almost exclusively to scientific researchers. The weather is, by all accounts, spectacularly hostile—constant gale-force winds, temperatures rarely above freezing, and seas that make the approach by boat genuinely dangerous.
The restriction isn’t about secrecy or military sensitivity. It’s about preserving one of the last places on Earth where a complete subantarctic ecosystem functions without any human footprint. No introduced species, no infrastructure, no trails, no garbage. The Australian government’s position is essentially: we have one of these and we’re not going to let anyone ruin it.
Lascaux Cave, France
The Lascaux cave paintings in the Dordogne region of southwestern France—created approximately 17,000 years ago—are among the most important archaeological sites on Earth. They depict horses, aurochs, deer, and abstract symbols in pigments that have survived for seventeen millennia. The cave was opened to the public in 1948 and received roughly 1,200 visitors per day through the 1950s. By 1963, the carbon dioxide, heat, and humidity generated by all those human bodies had caused visible damage to the paintings—green algae, white calcite deposits, and black fungal growth on surfaces that had been stable for 170 centuries until tourists showed up.
The cave was closed to the public in 1963 and has remained closed since. Even the researchers who monitor the paintings are limited in how often and how long they can enter. The French government built Lascaux II, a precise replica of the two most famous chambers, about 200 meters from the original, and later Lascaux IV, an even more elaborate facsimile. You can visit a copy of the cave. You cannot visit the cave. The originals sit in climate-controlled darkness, preserved by the absence of the very species that created them.
What forbidden zones actually tell us
The through-line across these places—and the dozens of others like them, from Mezhgorye in Russia to the Heard Island volcano to the closed military cities of the former Soviet Union—is that the reasons for restricting access are almost always more revealing than whatever’s behind the fence.
North Sentinel Island is forbidden because of an unresolved collision between indigenous sovereignty and the modern world’s inability to leave anything alone. Area 51 is forbidden because military secrecy, once established, takes on institutional momentum that outlives its original justification. The DMZ is forbidden because two countries that never signed a peace treaty have been in a frozen standoff for seven decades, and the buffer zone between them has accidentally become an ecological paradise. Lascaux is forbidden because we loved something to death and had to wall it off from ourselves. Svalbard is forbidden because someone had the foresight to build a backup plan for civilization and the wisdom to not turn it into a tourist attraction.
These aren’t just places you can’t go. They’re places that tell you something about how humans interact with the things they find most valuable—whether that’s a species, a secret, a painting, or a seed.
We cover forbidden zones, disputed territories, unrecognized states, and places erased from official maps across our Off The Map: A Global Atlas of Non-Existent Places course—a full atlas of the places the world doesn’t quite know what to do with.