In 2007, 52-year-old Slovenian endurance swimmer Martin Strel became the first person to swim the entire length of the Amazon River.

It took him 66 days to complete and, over the course of his journey, Strel faced threats such as pirates, sharks, and dengue fever. At 3,300 miles, it’s the longest open swim in history.

He shares his experience of the swim with Hunter Charlton. It’s an Ember Audio production for BBC World Service.

(Photo: Martin Strel pictured in London in 2009. Credit: Getty Images)