The team explores an area where no human has ever set foot, dropping nearly 400 meters into the deepest canyon in Oman in Southern Arabia.

Explorers head to Greenland in the Arctic, where they kayak through the world's largest fjord during the spring melt -- the most dangerous time of the year.

The naturalist visits uncharted territory in the Guiana Shield, finding wildlife that have never encountered humans.

Steve leads a team into the largest unexplored cave network on Earth below the jungles of Mexico, pushing further and deeper than anyone has gone before.

The team battle through the jungle into the heart of Indonesian Borneo, where a remote mountain range guards caves, holding secrets that could rewrite history.

Steve heads to the Himalayas to visit the last great unexplored river in Bhutan, which, according to legend, drops off the face of the planet at some point.