Islands are supposed to be sunny, peaceful, and warm – exotic locales where you spend time on the beach, maybe do a bit of snorkeling, and even enjoy a few fruity drinks. Except sometimes, none of that happens.

The world sports many deceptively beautiful islands, ones that look pleasant but are actually terrifying. From former nuclear test sites to places that are home to deadly creatures, these scary isles have more going on than we realized. And we wanted to know more.

We found out what people who’ve been to 10 of the most dangerous islands in the world said about them, and were left ready to just stay home. Vote up the islands you will most definitely take a hard pass on, too.

Photo: Jesse Allen / NASA Earth Observatory / Wikimedia Commons / Public domain

North Sentinel Island Natives Remain ‘All Set To Defend Their Land’

As one of the Andaman Islands, North Sentinel Island is located in the Bay of Bengal. It’s supervised by India, and visitors need permission to set foot on its shores.

Restricted entry and limited contact with the indigenous people serve two purposes. There’s a desire to protect the island and its population, as well as to prevent additional acts of violence that have involved past visitors.

During the late 19th century, European exploration of the island proved fruitless, while 20th-century interactions with the Sentinelese left the Indian government and anthropologist T.N. Pandit struggling to establish friendships. Pandit recalled his trips to the island:

We had brought in gifts of pots and pans, large quantities of coconuts, iron tools like hammers and long knives… But the Sentinelese warriors faced us with angry and grim faces and fully armed with their long bows and arrows, all set to defend their land.

In 1991, successful contact was made, but efforts to drop in relief after the tsunami in 2004 were met with aggression. In 2006, natives killed two fishermen for getting too close to the island, and in 2018, the death of John Allen Chau demonstrated how dangerous it could be to approach its shores.

Chau attempted to spread Christianity on North Sentinel Island, first getting shot at with arrows on approach – only to return the next day. The natives proceeded to kill Chau. To maintain peace and the integrity of the island itself, his body was never recovered.

Pandit commented on Chau’s death in 2018, pointing out:

During our interactions they threatened us but it never reached a point where they went on to kill or wound. Whenever they got agitated we stepped back… I feel very sad for the death of this young man who came all the way from America. But he made a mistake. He had enough chance to save himself. But he persisted and paid with his life.

  • Area (km sq.): 72.0

Photo: Prefeitura Municipal de Itanha / Wikimedia Commons / CC BY 2.5

Ilha De Queimada Grande Is So Overrun With Lethal Snakes, It’s Illegal To Go There

Located off the coast of Brazil, Ilha de Queimada Grande is home to as many as 4,000 golden lancehead pit vipers – one of the most lethal snakes on the planet. Also called Snake Island, the landform is roughly 110 square acres of predator-free rainforest, rocks, and grassy areas for the lethal snakes to roam.

A golden lancehead pit viper bite can be lethal within hours without treatment, and because the island is so dangerous, Brazil has forbidden humans from visiting. Exceptions can be made, but a medical professional is required to accompany anyone setting foot there.

When Tara Brown from 60 Minutes received permission to visit Snake Island in 2019, she explained what it entailed:

A full medical team, an ambulance on the mainland on standby, a defibrillator, anti-venom, respirators. Everyone took it quite seriously… I discovered I’m pretty spineless. The setting is very remote, it’s very hot, highly vegetated, and you’re pulling yourself up to get to the top. To my mind, there could be a snake anywhere and you’re always on high alert, and a big part of me was saying, “Oh no, please don’t let there be a snake there.”

During the 1910s, the island’s lighthouse required human maintenance. According to local legend, the last lighthouse keeper and his family were killed when snakes chased them out of their home, fell out of the trees, and bit them. The lighthouse has been automated since the early- to mid-20th century, but occasional visits by the Brazilian navy are still necessary.

  • Located In: Angra dos Reis, Brazil

Coiba Island Was Home To One Of The World’s Most Dangerous Penal Colonies

In 1919, criminal and political prisoners first arrived at the “most severe prison” in Panama, housed on Coiba Island. The remote location housed more than 3,000 individuals from 1919 to 2004 and was the site of torture, brutality, and horrific conditions for decades.

Over time, Coiba Island had roughly 30 camps built by the prisoners themselves, with no furniture, windows, or bathrooms. The extreme conditions tested their mental sanity, as did torture techniques used by their captors. According to US Army Ranger Chuck Holton:

They had this ritual for new prisoners; the guards would take them into the jungle, blindfold them, line them up and have a mock execution. They would put guns to them, count down “three, two, one, fire,” intimidating them.

Holton called it an “absolutely malicious” place, in large part because “everything on that island wants to bite you; everything is poisonous.” He also talked about what he saw on his first visit:

There were some political prisoners… being held there on the island, but what we didn’t know was there were a few cells that were packed with people… The guards that were left there told us not to go in as they all had AIDS. We realized that several of the men in the cell had perished in the days before we got there. The dead had been left with the living; you can imagine the smell of several corpses that had been rotting.

  • Located In: Panama

Visiting Miyake-Jima May Require A Gas Mask

As a destination for avid swimmers, hikers, and birdwatchers, Miyake-jima sits off the coast of Japan. It’s also home to Mount Oyama, an active volcano, that regularly spews poisonous sulfuric gas.

Everyone on Miyake-jima is required to carry a gas mask, which wasn’t enough to protect the residents during a volcanic eruption in 2000. Alarms blare to alert people when it becomes necessary to put their masks on. The airport and the tourist store both sell gas masks.

When Mike Byrnes was assigned to Miyake-jima as an English teacher in 2014, he experienced firsthand what it was like to live there:

In regards to “Gas Mask Island,” like many things on the internet, this was something that was blown out of proportion. Sulfur gas does leak out of Mt. Oyama due to an eruption in 2005; however, people haven’t had to wear gas masks for years and [it] is only a precaution if the gas levels get too high.

Alfredo Petrov, a visitor to the island in 2010, noted:

Electronic SO2 monitors were set up all around the island, with sirens warning the public when to put on their gas masks. Gas masks are occasionally still necessary, depending on wind direction and the volcano’s mood…. Agriculture is still moribund, perhaps because no one wants to invest money with the insecurity of potential future gas eruptions and no one makes gas masks for chickens and cattle.

  • Located In: Tokyo, Japan
  • Area (km sq.): 55.44

Being On Bikini Atoll Feels Like A Visit To ‘The End Of The World’

During the 1940s and ’50s, Bikini Atoll, an island within the Marshall Islands chain in the Pacific Ocean, was a US military nuclear testing site. At the time, residents were relocated to nearby Rongerik and Kwajalein atolls before arriving at Kili Island in 1948.

Indigenous Bikinians returned to their atoll during the late 1960s and the population rose through the 1970s. Radiation levels left much of the food and water too dangerous for human consumption, with residents also experiencing health effects from radiation.

Continued clean-up, relocation efforts, and monetary aid left most native Bikinians living off the island, with scientists and caretakers as the lone inhabitants. Diving and sportfishing are common, although they must be done carefully.

When S.C. Gwynne visited the atoll in 2012, he saw firsthand how the deceptive beauty of the island could be:

Despite the natural beauty, it is impossible to walk anywhere, or look anywhere, and escape Bikini’s nightmare history. Every man-made object on the island is an artifact either of the bomb tests or of some failed attempt to help the Bikinians return to their home… There is a sense, while on Bikini Atoll, of being at the end of the world.

  • Located In: Marshall Islands

Sharks Patrol The Seas Around Réunion Island

As an island under French authority, Réunion Island is open to tourists and the like – but swimming and surfing is prohibited. Located in the Indian Ocean, Réunion is home to nearly 900,000 people and was the site of more than 50 shark attacks between 1988 and 2016.

In 2015, Rodolphe Arriéguy was attacked while surfing in the waters around the island. His friend, Erwann Lagabrielle, was with him at the time and described the event:

The water was white foam and then the white turned to pink and the pink turned to red… I swam to my friend and that was the most frighting thing – I was swimming against my own instinct. The shark swam away and I knew in most cases there was no re-attack. So, once the bleeding stopped I knew he was going to survive.

Arriéguy survived but lost one of his arms.

Eleven shark-related fatalities from 2011 to 2021 included the demise of Adrien Dubosc in 2017. According to local officials, Dubosc “was in the water with two friends, when a shark attacked him, biting his right thigh, and his groin area. The victim was pulled out of the water, and emergency workers arrived very quickly. Despite cardiac massage, he died within half an hour of the attack.”

In 2019, one man disappeared off the coast of the island, while three fellow surfers escaped harm. The unidentified man was later found dead. That same year, a 44-year-old Scottish man was attacked off Réunion Island, later identified by the wedding ring on his hand when it was found in the stomach of a shark.

Reportedly, Ramree Island Was Once The Site Of A Massacre By Crocodiles

As the site of several World War II battles, Ramree Island off the coast of Myanmar (Burma) in the Bay of Bengal is also known for deadly crocodiles populating its shores. Japanese forces took control of the island in 1942 and, in 1945, British and Indian forces prepared to seize the location as a strategic airbase.

As British and Indian troops pushed the Japanese off Ramree Island, many Japanese fighters took refuge in the swamps. It was there that, according to some versions of the battle, hundreds of the men were devoured by crocodiles.

Bruce Wright, a scientist who fought as a member of the Royal Canadian Navy, detailed his experience:

That night [February 19, 1945] was the most horrible that any member of the [motor launch] crew ever experienced. The scattered rifle shots in the pitch-black swamp punctured by the screens of wounded men crushed in the jaws of huge reptiles, and the blurred worrying sound of spinning crocodiles made a cacophony of hell that has rarely been duplicated on earth. At dawn, the vultures arrived to clean up what the crocodiles left behind… of about 1,000 Japanese soldiers that entered the swamps of Ramree, only about 20 were found alive.

Another scientist, Steven G. Platt, challenged this version of event in 2001, noting Wright wasn’t on the island at the time of the massacre. Platt interviewed island residents who indicated only 10 to 15 men may have been attacked by crocodiles, if at all.

Regardless of the exact threat presented by the crocodiles of Ramree, the presence of the predators was of concern to soldiers in the Pacific Theater. Robert Duff, one of the British troops who fought there, recalled:

We had some very hard fighting… but after a few weeks we managed to push the [Japanese] to the swamp on the other side of the island, which was full of crocodiles. They decided to take their chances in the swamp rather than surrender… Only a handful came out alive.

  • Located In: Myanmar

‘Confident’ Dingoes Roam Fraser Island And Toxic Jellyfish Surround It

Officially the largest sand island in the world, Fraser Island (recently restored to its Aboriginal name, K’Gari) is also where some of the world’s most deadly jellyfish live. In 2019, two women were stung by Irukandji jellyfish, whose venom can result in cardiac and respiratory problems alongside terrible pain. The following year, numerous additional stings by the jellyfish prompted local officials to voice concern:

We’re urging everyone to stay out of the water entirely on that western side of the island while conditions are hot and humid.

One tip offered to visitors to help with jellyfish threats is “always have vinegar on you.” Alongside jellyfish, sharks swim offshore, dingoes and crocodiles are present, and even sand dunes pose a risk for drivers.

When the Richards family visited Fraser Island in 2021, they saw dingoes (albeit not for the first time). According to Tim Richards:

First day we were here and had all our washing out – a bikini, dress and boardshorts went missing and then were ripped up the following morning when we woke up. It’s pretty unusual… The next night we had a pack of dingoes roaming around the marquee with the lights off just circling, and circling. There were about three to six I think. Normally we just have a lone dingo roaming around but they’ve been pretty confident this time.

  • Located In: Queensland, Australia
  • Area (km sq.): 1840.0

Once A Quarantine Station And Home To A Mental Asylum, Poveglia Island Is Hauntingly Quiet

During the outbreak of the Black Death during the Middle Ages, as many as 160,000 plague-sufferers were reportedly sent to Poveglia Island, off the coast of Venice, Italy, where they ultimately passed and were cremated. According to lore, a significant portion of the island’s soil comprises ash from human bodies.

By the late 18th century, Poveglia served as a quarantine station for visitors to nearby Venice. The facilities on the island were later transitioned to house the mentally ill, many of whom were experimented upon while there.

The number of deaths and reported abuse on Poveglia has resulted in its other name: “The Island of Ghosts.” While visiting Poveglia is forbidden, some individuals have ventured there. Visitor Scott MacKinnon, who claimed to have spent the night, recalled what it was like:

My mind became a slave to the various creaks and moans of the building, working overtime and twisting my imagination like a drug-induced hallucination. It was all too much for me, but I had nowhere to run. I grabbed my pack and bolted to the dock about 50 feet away praying for rescue, but I was imprisoned and escape was impossible….

Unable to sleep, MacKinnon:

…stayed completely still with my eyes and ears wide open and my brain conjuring up horrible scenarios surrounding my untimely death at the hands of the living dead.

In 2014, photographer Mike Deere managed to persuade a local captain to take him to the island, although the courier refused to step foot on Poveglia himself. Deere’s impression of the island was one of “peace and serenity – it was a very quiet place.”

Gruinard Island Has Been Decontaminated, But Potential Visitors Are Skeptical

Also called “Anthrax Island,” Gruinard Island was a test site for biological weapons during World War II and is located off the west coast of Scotland, less than a mile from the mainland.

The tests involved putting anthrax spores into bombs and detonating them to see how long it took the effects to set in. Sheep, instead of people, were the test subjects.

Gruinard Island was declared safe to visit in 1990, thanks to decontaminating it with tons of formaldehyde. A resident of Laide, Scotland, Jane Richardson, noted that a farmer visits the island regularly to tend the sheep grazing on it, while Jean McClean admitted that going to Gruinard seemed fruitless: “There’s nothing there… so why take the chance?”

The island’s caretaker, who makes trips to the island to hunt deer, described “lovely fields of bluebells [that] cover the island every spring.” He also said:

I’m not afraid in the remotest of getting anthrax. Nobody here has ever come down with it, so I don’t see why anyone ever would… I’d say there’s more chance of a hind [deer] shooting back at me.

  • Located In: Inner Hebrides, Scotland
  • Area (km sq.): 1.96