Fraser Island, Australia
The seas surrounding Fraser Island, to the south-east of Queensland, are a certified no-go zone. That is unless you mind swimming with sharks, saltwater crocodiles and box jellyfish, while battling strong rip currents. Head inland and you're likely to bump into some of the world's deadliest spiders, as well as dingoes, which are known to occasionally attack humans.
This part of the world is great white territory. A few miles off the coast lies Shark Alley, a small channel of water between Dyer Island and Geyser Rock. It is home to a colony of around 60,000 fur seals, which attracts swarms of great whites, and subsequently, hordes of camera-weilding tourists in shark-proof cages.
If this sobering sign that greets visitors to Hanakapiai Beach in Hawaii is accurate, at least 83 people have drowned here over the years. Like much of the Kauai's Napali Coast, rip currents and powerful waves make swimming a highly dangerous activity. There have even been reports of drowning victims being swept out to sea while paddling in the shallows.
This popular sandy beach in Recife, Brazil, attracts sunseekers throughout the year, and was once considered shark-free. But since 1992, at least 50 shark attacks have been recorded here, including 19 which were fatal. Environmentalists say the destruction of the region's coastal ecosystem, caused by fishing boats that trawl ever closer to the coastline, is to blame.
And if that wasn't reason enough to watch your back, the city has problems with violent crime.
Each year, between October and April, countless swarms of box jellyfish force the closure of hundreds of beaches across northern Australia. They are among the most venomous creatures in the world, and have been responsible for at least 70 deaths since 1883. Stings are so agonisingly painful that some victims suffer cardiac arrest before they can reach the shore.
Volusia County, Florida
According to the International Shark Attack File (ISAF), a database for reported shark attacks, more unprovoked shark attacks have taken place off the coast of Volusia County in Florida than in the whole of South Africa – 235 in total, since 1882. None, however, have been fatal. You're also more likely to be struck by lightening in Florida than anywhere else in North America: 71 deaths were caused by lightening in the state between 1997 and 2006.
Come on in, the water's lovely! Chowpatty Beach in Mumbai has long held a reputation as one of the world's most polluted, and the sea here is entirely unfit for swimming. The beach, however, shouldn't be avoided in early September, when Mumbai's residents flock here to celebrate the Hindu festival of Ganesha Chaturthi.
Copacabana Beach, Brazil
It's not quite in the same league as Praia de Boa Viegem in Recife, with only six confirmed shark attacks since 1931, but the greater danger here is petty crime. Theft and robbery are commonplace, so leave your camera and wallet in the hotel safe.
This Unesco World Heritage Site is dangerous for two reasons: nuclear radiation and sharks. It was the site of more than 20 nuclear weapons tests between 1946 and 1958, and – although the islands were declared "safe" by US boffins in 1997 – their original inhabitants have refused to return, and eating locally-grown produce is not advised. So no chomping on fallen coconuts. Furthermore, the lack of fishing in the area during the last 65 years means that sea life – including sharks – has flourished, which, along with the numerous shipwrecks in the region, attracts hundreds of divers each year.
This section of the northern Californian coastline, from Big Sur to Bodega Bay, is the location of 11 per cent of all recorded attacks on humans by great white sharks, according to the ISAF. The large population of marine mammals – including seals, otters and sea lions – is responsible.
Kilauea, Hawaii
Be careful where you place your towel. The black sand beach at Kilauea, on the Hawaian island of Kauai, sits next to one of the world's most active volcanoes. It has been continuously erupting since 1983, spewing lava into the ocean. There has also been 102 unprovoked shark attacks in Hawaii – eight of which were fatal – since 1828.
Some claim that the word "Zipolite" comes from the indigenous Nahuatl language, and it means "beach of the dead". This small but well-visited stretch of sand, popular with nudists and backpackers, is renowned for its big waves and dangerous rip currents. A volunteer lifeguard team was established in 1995, which has reduced the number of drownings dramatically, and between 2007 and 2009, there were no reported deaths and the lifeguards logged 180 rescues.
Amazon beaches, Brazil
A paddle in the Amazon means you're likely to be sharing the water with piranhas, anacondas and electric eels. Stay on the shore.
Staithes, UK
Staithes Beach in Yorkshire has been described by the campaign group Surfers Against Sewage as "the worst in Europe", due to its polluted waters, and it is among 41 in Britain to have failed to meet basic European standards, according to the Marine Conservation Society. Others include Looe in Cornwall, St Andrews in Fife, and St Anne's in Blackpool.
