On our increasingly crowded planet, there are still a few remote areas where nature has the upper hand: the last great wildernesses. In this series, Simon Reeve attempts to journey across four of them, venturing further into the unknown than he ever has before, in a bid to unlock their secrets, and experience the natural world at its most beautiful and fragile.

Simon explores the Pacific Ocean's spectacular Coral Triangle, Africa's vast Congo Rainforest, the sweeping Kalahari desert, and the awe-inspiring landscape of Patagonia. Along the way, Simon embeds himself with the people who make their homes in the wild, to understand how they live alongside nature, and what we can all do to preserve the planet's greatest wonders for future generations.