The final stage of Simon Reeve's journey. Simon crosses the Atacama desert - the driest place on earth - and climbs 15,000 feet into the Andes. In Argentina he dodges bees as he hunts for honey with the indigenous Wichi people, whose lives are threatened by deforestation. In Brazil, Simon visits Sao Paolo, the biggest and perhaps most dangerous city in the Southern Hemisphere.

• Simon Reeve