What are the toughest adventures on the planet? Which extreme exploits push willing participants to their mental and physical limits? BBC Travel answers these questions with few high adrenalin, extreme travel locations:

1. Rafting Franklin River, Tasmania

The trip down the Franklin ending at Sir John Falls, takes between 8  and 14 days, depending on the state of the river.

2. The Marathon of Sand, Morocco

Six marathons run over six days in the middle of the Sahara Desert! Competitors must carry all of their personal belongings and food in a backpack. They run, walk or simply stumble a grand total of 250km in temperatures approaching 50C.

3. The Snowman trek, Bhutan

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. The trekcrosses 11 passes of more than 4,500m, following trails through isolated farms, against an eye-bulgingly beautiful backdrop of Himalayan peaks.

4. Tour d’Afrique cyclism, starts at the Pyramids of Giza

You will need four months to complete the whole of this peddle-powered trans-African odyssey.

5. Surfing the “Devil Wave”, Tasmania

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.