The World's Most Dangerous Islands

From Snake Island to Anthrax Zones: 10 Lethal Islands

From afar, islands often look like slices of paradise—turquoise waters, palm-fringed beaches, and sun-soaked serenity. But not all islands are created equal. Some are riddled with danger, where every step could be your last. These aren’t your dreamy honeymoon destinations—they’re real-life horror stories wrapped in blue. If you’ve ever wondered where not to go, here’s your essential list of the worst islands you could ever visit.

1. Snake Island, Brazil: The Viper's Lair

Ilha da Queimada Grande, or Snake Island, is easily one of the most terrifying places on Earth. Located just 33 kilometers off the coast of Brazil, this island is home to the golden lancehead viper (Bothrops insularis), a snake so venomous that a single bite can cause brain hemorrhaging, kidney failure, and severe tissue necrosis. It's estimated that there’s one snake per square meter, making a casual stroll virtually impossible without stepping on danger. Due to its intense threat to human life, the Brazilian government has prohibited public access. Only scientists with special permits are allowed to visit—and even they must bring a medical professional. The lighthouse that once stood on the island has long since been automated. Locals whisper of people who went and never returned.

2. North Sentinel Island, India: The Island That Kills Strangers

Tucked away in the Bay of Bengal lies North Sentinel Island, home to the Sentinelese—one of the last uncontacted peoples on Earth. The Indian government enforces a strict exclusion zone around the island, protecting both outsiders and the tribe itself. The Sentinelese have fiercely defended their isolation, using bows, arrows, and spears against anyone who dares approach. American missionary John Allen Chau ignored these warnings in 2018 and was killed upon arrival. Earlier attempts at peaceful contact by anthropologists have seen limited success, with exchanges involving coconuts and gifts. Still, even those with good intentions are met with suspicion. With no immunity to modern diseases, contact with outsiders could be fatal for the tribe—making this island not only dangerous to visit but ethically untouchable.

3. Ramree Island, Myanmar: Death by Crocodile

Ramree Island might look like a tropical escape, but its marshy terrain tells a darker tale. During World War II, in one of the most gruesome wildlife massacres ever recorded, hundreds of Japanese soldiers fled into the island’s mangrove swamps after being cornered by British troops. Unfortunately, the marshes were home to a vast population of saltwater crocodiles—the largest and most aggressive reptiles on the planet. Eyewitness accounts and local legends claim that most of the soldiers were eaten alive. While historians debate the death toll, the British military documented the carnage, stating the crocs turned the swamp into a feeding ground. Even today, the area remains teeming with crocodiles, dense mudflats, and disease-carrying insects. This is not the place for a casual hike or jungle adventure.

4. Miyake-jima, Japan: Gas Mask Island

Located in the Izu archipelago, about 180 kilometers south of Tokyo, Miyake-jima is a volcanic island unlike any other. In June 2000, Mount Oyama, the island’s active volcano, erupted violently, releasing huge plumes of sulfur dioxide gas into the air. Residents were forced to evacuate for five years. Even after their return, they were required to carry gas masks at all times, as toxic fumes continued to leak from the ground. Warning alarms still sound when gas levels rise, and sulfur concentrations are monitored constantly. In addition to the air hazard, the island experiences thousands of mini-earthquakes every year, a reminder of the volcano's simmering presence. While the island is now open to visitors, exploring Miyake-jima feels more like walking through a disaster-prep drill than a vacation.

5. Gruinard Island, Scotland: Anthrax Island

During World War II, the British government chose Gruinard Island off the coast of Scotland for top-secret biological warfare experiments. Scientists released deadly anthrax spores to test their impact on livestock and potentially, enemy forces. The trials killed countless sheep and contaminated the island so badly that it was declared uninhabitable for nearly half a century. In the 1980s, a major decontamination effort was launched using tons of formaldehyde and seawater, and Gruinard was officially deemed safe in 1990. Still, its grim legacy lives on. Locals remain wary, and visitors are rare. While the soil is supposedly clean, some scientists argue that anthrax spores could still linger deep underground. If you do visit, avoid touching the soil or grazing areas—just in case history hasn’t fully faded.

6. Komodo Island, Indonesia: Land of the Dragons

Komodo Island may be a national park and UNESCO World Heritage Site, but behind its rugged beauty lurk prehistoric predators. Home to over 2,500 Komodo dragons—the world’s largest lizards—this island is no place to let your guard down. These muscular reptiles can grow up to 3 meters long and weigh over 70 kilograms. They're fast, aggressive, and have venomous bites that cause extreme blood loss and infection. Tourists are advised to always travel with a licensed guide and stick to designated trails. Komodo dragons have attacked humans in the past, with incidents ranging from bites to fatalities. They’re drawn to the scent of blood, so anyone menstruating or with open wounds is told to stay away. This wild island is better admired cautiously than conquered.

7. Poveglia, Italy: The Island of Ghosts

Poveglia sits in the Venetian Lagoon and is known as one of Europe’s most haunted locations. In the 14th century, it was used as a quarantine site for plague victims—many of whom were left to die in mass graves or burned alive. Later, in 1922, the island became home to a mental asylum where rumors of cruel experiments and tortured souls began. Though abandoned in 1968, Poveglia’s eerie ruins remain: crumbling buildings overtaken by ivy, and stories of shadowy figures and ghostly screams echoing through the hospital walls. The soil itself is said to be mixed with human ash. Today, the island is off-limits, and special permission is required for access. But ghost hunters and curious thrill-seekers still try to sneak in—for a brush with the paranormal.

8. Farallon Islands, USA: Radioactive and Shark-Infested

Located 30 miles west of San Francisco, the Farallon Islands are a cluster of rocky outcrops with a dark past. Between 1946 and 1970, over 47,000 barrels of radioactive waste were dumped in nearby waters, much of it undocumented. Though no immediate threat has been confirmed, the legacy of contamination makes this area unsettling. But radiation isn’t your only concern. The islands are also surrounded by elephant seals—favorite prey for great white sharks. These waters are one of the world's most active shark hunting grounds. The islands are closed to the public and only accessible to researchers and wildlife personnel. For curious visitors, boat tours operate nearby, but you’ll want to keep your distance unless you're ready for Jaws meets Chernobyl.

9. Reunion Island, France: Shark Attack Central

This idyllic French island in the Indian Ocean has gained global notoriety for something far less inviting: an unprecedented spike in shark attacks. Since 2011, Reunion Island has seen over 20 major shark incidents, including 11 fatalities. The high concentration of bull and tiger sharks close to shore has led to restrictions on swimming, surfing, and diving in many parts of the island. Experts believe changes in fishing practices, reef degradation, and local currents have brought sharks closer to humans. In one chilling case, a man snorkeling was killed and his hand—with wedding ring still on—was later found inside a captured shark. Despite its waterfalls, creole culture, and volcanic landscapes, if you value your limbs, keep your beach days dry on this island.

10. Saba, Caribbean Netherlands: Hurricane Magnet

Saba is a tiny volcanic island known for its dramatic cliffs and diving reefs, but it also sits directly in the path of the Atlantic’s fiercest hurricanes. Though just five square miles, it faces colossal damage potential during hurricane season (June to November). With limited infrastructure, supplies, and escape routes, getting stuck here during a storm can be terrifying. In past hurricanes, buildings were flattened, roads washed out, and communication lines severed. The airport—one of the world’s shortest commercial runways—becomes unusable in bad weather. Locals prepare extensively, but for visitors, this level of risk can be overwhelming. While Saba is a stunning destination during calm months, nature rules the island during hurricane season, and when the storms come, there’s nowhere to hide.

Last Word on the World's Most Lethal Islands

Some islands offer soft sand and sunset cocktails. Others offer venom, ghosts, and radioactive soil. While adventure is what we live for, there’s a fine line between thrilling and fatal. These islands test the limits of survival—and unless you're well-prepared (or a professional researcher), it’s best to admire them from afar.