Think of islands, think of tropical idylls, fringed by palm trees and drenched in sun, says Helen Pilcher, but not all islands are created equal. From dangerous reptiles to rising water levels and radioactive fallout, here are ten of the world’s deadliest islands.
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Deadliest islands in the world
Ilha da Queimada Grande, Brazil
Ilha da Queimada Grande, otherwise known as Snake Island, is a small, rocky island off the coast of southern Brazil. It covers an area of less than half a square kilometre, yet is home to more than 2,000 extremely venomous golden lancehead vipers.
When rising sea levels cut them off from the South American mainland, some 11,000 years ago, the snakes became trapped. With no mammals and few ground animals to hunt, the reptiles by eating migratory birds. This may explain why their venom is so deadly – where other venomous snakes can bite and then track their flagging prey, the golden lancehead viper needs to kill its prey quickly, before it flies away.
In 1985, Brazilian authorities made the island a protected ecological area to safeguard the snake, which is found here and nowhere else. Since then, the island has been closed to the public, which is just as well. Although there are no statistics on the mortality rate of this specific viper’s venom, other lancehead snakes cause more human deaths than any other group of snakes in either North or South America.
Gruinard Island, Scotland
No one lives on Gruinard Island, a small, remote island off the west coast of Scotland. With good reason. In 1942, UK scientists set off bombs containing anthrax spores as part of a biological weapons experiment.
Eighty sheep, which had been deliberately taken to the island and left in a crate facing the blast, duly contracted anthrax and then died. The experiment, orchestrated by scientists from Porton Down (the UK’s chemical and biological warfare research facility), was kept secret for decades until environmental activists blew the whistle.
Anthrax spores can last for many decades, and in 1986, the British government authorised the island’s decontamination. Seawater containing formaldehyde was used to spray the island, and the contaminated topsoil was taken away. Now, Gruinard Island – or Anthrax Island as it is also known - is anthrax free, but it remains uninhabited by humans.
Réunion Island, Indian Ocean
A tiny dot in the Indian Ocean, Réunion Island has many threatening features. In its southeastern corner, the Piton de la Fournaise volcano has erupted more than 100 times since 1640, and continues to rumble on.
Out to sea, sharks patrol its waters. From 2011 to 2019, there were around 30 shark attacks, resulting in 11 fatalities. Now, swimming and water activities are restricted or banned in many coastal areas.
Located in a cyclone-prone part of the Indian Ocean, the island is also at risk from intense winds, flooding and landslides. Most notably, in 2014, Cyclone Bejisa caused widespread destruction, with wind speeds of up to 150 kilometres per hour.
Add in steep cliffs, deep ravines and rapidly changing weather patterns, and Réunion Island is to be treated with respect. That said, it’s well prepared and has excellent infrastructure, so to the 900,000 or so people who live there, it’s still a beautiful place to live.
Bikini Atoll, Marshall Islands
Bikini Atoll is not one but 23 different islands all surrounding a large, central lagoon. It is famous because it was used as a nuclear weapons testing site by the United States between 1946 and 1958.
One hundred and sixty seven residents were forcibly relocated, to make way for 23 nuclear tests at seven test locations. The explosions unleashed huge amounts of energy, equivalent to 77 million tons of TNT, contaminating Bikini Atoll with more than 7 million curies of radioactive fallout.
To this day, those who used to live on Bikini Atoll are prohibited from returning because radioactivity levels remain dangerously high. Special permission can be obtained to dive in the waters around the islands, but permanent habitation remains prohibited.
Miyake-jima, Japan
Miyake-jima is a small, circular island in the Philippine Sea, around 180 kilometres southeast of Tokyo. The entire island is a giant, active volcano, which last erupted in 2000, prompting a full evacuation of the island’s 2,000 or so inhabitants.
In the years that followed, volcanic activity continued, spewing toxic sulfur dioxide gas into the atmosphere. When the residents were finally allowed to return, in 2005, they were required to carry gas masks with them at all times.
The island became known as “Gas Mask Town,” but even though the volcano continues to expel sulfur dioxide, gas masks are no longer mandatory. A special alarm system has been fitted, which monitors the volcanic gases and warns the residents if levels become too high.
Saba, Caribbean Netherlands
Once you land, Saba is a paradise for hikers, divers and wildlife lovers. Once you land. Saba Island makes the list, not because the island itself is deadly, but because the runway that serves its only airport is reputed to be the most dangerous in the world.
A Caribbean island and the smallest special municipality of the Netherlands, Saba Island is both mountainous and volcanic. When they built its airport, called Juancho E. Yrausquin, there wasn’t much room for the runway. So, they sandwiched a small 400 metre strip of tarmac between cliffs on the one side and the ocean on the other.
This is the world’s shortest commercial airport runway. Landing a plane here requires skill, precision and nerves of steel. In February 2023, a Birtten-Norman BN-2B-20 Islander plane was badly damaged when it missed the runway and suffered a ‘hard landing’. Thankfully there was no loss of life. Not so, when a similar incident occurred in 1971. Although the passengers in the plane all survived, a goat on the runway was not so lucky.
Rapa Nui, Chile
For a long time, the story of Rapa Nui (Easter Island) was one of exploitation and greed. The Polynesians who lived there cut down more trees than could regrow, leading to ecological and societal collapse. Before long, the only human figures left were the tall, stone statues or ‘moai’ keeping watch over the South Pacific.
Recent studies, however, tell a different story. By the end of the nineteenth century, the population size had dropped dramatically, but not just because of tree felling. First, European sailors brought smallpox, tuberculosis and syphilis to the island.
Then, Peruvian slave traders kidnapped around 1,500 people – roughly half the population - who were forced to work in the Peruvian guano mines and other industries. A handful later returned, but when they did, they reintroduced smallpox, triggering a deadly epidemic that ripped through the remaining community. By 1877, there were only about 100 native Rapa Nui left on the island. Their island was not deadly, but their treatment by others was.
Ellesmere Island, Canada
Ellesmere Island makes the list because it is widely considered to be the coldest island on the earth. Situated in the Canadian Arctic Archipelago, Ellesmere Island is Canada’s northernmost landmass and third largest island.
Although just a smidgen’ smaller than Great Britain, less than 200 people live here. Grise Ford, which means ‘the place that never thaws’, is the biggest of three settlements. It is also one of the coldest inhabited places in the world, with an average yearly temperature of -16.5 oC.
Snow and ice persist year round, and parts of the island are covered with permanent ice caps and glaciers. For those hardy enough to visit, however, the scenery and wildlife will not disappoint. Think polar bears, Arctic foxes, musk oxen and narwhals, but wrap up warm and don’t forget your thermals.
North Sentinel Island, Bay of Bengal
When a helicopter flow over North Sentinel Island in 2004, the indigenous tribespeople that live there reacted by pelting it with arrows, spears and stones. Their message was clear. Stay away. We will harm you.
North Sentinel Island is a densely forested landmass about the size of Dundee. One of the Andaman Islands, it is home to the 100-or so members of the Sentinelese, a hunter-gatherer tribe that has actively repelled contact with the outside world since they were discovered in the late nineteenth century.
One year after the helicopter incident, the Indian government established a 9 kilometre exclusion zone around the island, to protect the islanders and respect their autonomy. Those who intrude, do so at their peril. In 2006, two fishermen were killed by the Sentinelese after their boat drifted ashore. And in 2018, an American missionary met the same fate after he landed on the island and tried to convert the tribe to Christianity.
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