From completing Bhutan’s Snowman trek to cycling the Tour d’Afrique, these feats of endurance and endeavour push you to your mental and physical limits.

What are the toughest adventures on the planet? Which extreme exploits push willing participants to their mental and physical limits? These feats of endurance, endeavour and -- dare we say lunacy -- will stir up the most jaded adrenaline junkie.

Rafting the Franklin River
Tasmania is an earthly paradise for lovers of adventure, and rafting the fearsome Franklin River is one of the Apple Isle’s ultimate thrills. The trip down the Franklin, starting at Collingwood River and ending at Sir John Falls, takes between eight and 14 days, depending on the state of the river. A 100km journey that begins in the beautiful Irenabyss Gorge ends with the fury of the five-kilometre-long Great Ravine, a stretch of white water which boils with dangerous rapids.

Experienced rafters can tackle the Franklin independently if they are fully equipped and prepared, but for everyone else, tour companies such as World Expeditions, Rafting Tasmania and Water By Nature offer complete wilderness rafting packages.

Running the Marathon des Sables
Considered by some to be the world’s toughest foot race, the infamous Marathon des Sables (Marathon of the Sand) consists of six marathons run over six days in the middle of the Sahara Desert in Morocco. Sound mad? It is. But this masterpiece of masochism still draws devotees from all around the world.

Competitors must carry all of their personal belongings and food in a backpack, while the organisers lay on water and shelter at the end of each stage. Competitors run, walk or simply stumble a grand total of 250km in temperatures approaching and even sometimes in excess of 50C, with the longest single stage registering a palpitation-inducing 88km.

Completing the Snowman trek
Widely considered to be one of the hardest treks in the world, only a handful of people each year attempt this 25-day route through Lunana, the most remote region of Bhutan. It is expensive, gruelling and success is far from certain. Of the few who do set out along the high mountain passes, less than half complete the route due to altitude sickness or heavy snowfall.

The trek, which starts in Drukgyel Dzong and ends in Sephu, crosses 11 passes of more than 4,500m, following trails through yak herder settlements and isolated farms, against an eye-bulgingly beautiful backdrop of Himalayan peaks.

The window of opportunity for this high altitude undertaking is vanishingly small – the short season when the paths are likely (but not guaranteed) to be open runs from late September to mid-October.

Cycling the Tour d’Afrique
You will need four months to complete the whole of this peddle-powered trans-African odyssey. First held in 2003, the Tour d’Afrique starts at the Pyramids of Giza and threads its way down the continent to Table Mountain.

Riders clock up a total of 11,869km at an average of more than 112km a day as they follow the back roads through Egypt, Sudan, Ethiopia, Kenya, Tanzania, Malawi, Zambia, Botswana, Namibia and finally South Africa.

The route takes in a handful of Africa’s most iconic sights, including the Karnak Temple, the Ngorogoro Crater, the Great Rift Valley, Victoria Falls, Fish River Canyon, the Okavango Delta and the Dune Sea of the Namib Desert. The main danger on this journey is dehydration.

Surfing the “Devil Wave”
Take an end-of-the-world location, add huge, unpredictable and dangerous waves and throw in some hungry Great White Sharks for good measure – this is the forbidding recipe for Shipstern’s Bluff, one of world’s most extreme surf spots.

Once known as the Devil’s Point, this remote area off the tip of Tasmania’s Tasman Peninsula, is accessible only by boat, jet ski or a two-hour bush walk. That means you are a long way from civilisation – and specifically, a hospital – if anything goes wrong. And it frequently does at Shipstern, where the Southern Ocean and the Roaring Forties conspire to whip the cold water into a monstrous right-hander.

Doing the other Coast to Coast
Despite sharing a name with the UK's Coast to Coast, a famous meander through the countryside in the north of England,  the Antipodean version traverses the rather more rugged terrain of New Zealand’s South Island. The adventure starts at Kumara Beach on the Tasman Sea and finishing at Sumner Beach on the Pacific and crosses the formidable mountains of the Southern Alps.

The race involves a 140km stint on a bike (which breaks down into three stages of 55km, 15km and 70km), followed by a 36km run (33km of which crosses the Alps) and finally a 67km kayak down the Grade II white water of the Waimakariri Gorge, New Zealand’s answer to the Grand Canyon.

Incredibly, the fastest competitors complete this trial in slightly less than 11 hours. Take heart and stiffen the sinews, though: the oldest competitor to undertake the challenge was 75, while the youngest was just 15.

Base jumping into the Cave of the Swallows
The idea of Base jumping off anything is enough to send most travellers scuttling for the safety of a spot behind the sofa, so what about doing it into the mouth of a cave?

Sótano de las Golondrinas, or the Cave of the Swallows, is a huge limestone sinkhole near Aquismón, San Luis Potosi, Mexico. Its name comes from the many white-collared swifts and green parakeets that live in the holes in its walls. But the spectacle of them exiting and entering every day is not the only reason that the cave draws so many visitors.

The Cave of the Swallows is deep enough to accommodate a skyscraper, meaning about 10 seconds in freefall, and that has caught the imagination of those who enjoy plunging off fixed objects with only a packed parachute strapped to their back.

The article 'The toughest adventures on the planet' was published in partnership with Lonely Planet.