Having descended the Blue Nile in 1968 and in the process inadvertently inventing whitewater rafting the British Army explorer Major John Blashford-Snell was by 1972 looking for a new ruse to go off adventuring.

A trip to the Red Sea's remote Dahlak Archipelago with Sandhurst cadets the previous year was swiftly followed an expedition aiming to be the first people to drive from Alaska to Cape Horn.

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While North America proved pretty plain sailing when the Army team and their two Range Rovers hit the swamps and jungles of Central America things rapidly slowed down.

The Darien Gap remains to this day the only break in the 48,000km (30,000mi) Pan American highway, a vast swathe of virtually impassable tropical marshland and forest that forms the border between Panama and Colombia.

MORE: The British Army Officer Who Pulled Off One Of History's Greatest Cons

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