Undiscovered Worlds with Steve Backshall

This time Steve and his team is kayaking in the Arctic - they face perilous sea ice and have a terrifying encounter with a polar bear.

The explorer sets out to become the first person to reach the summit of a mountain in Greenland's Arctic wilderness, an expedition threatened by the impact of climate change.

Steve leads a team of experts including underwater cave explorer Robbie Schmittner, ex-Royal Marine Aldo Kane and diving camera operator Katy Fraser into Mexico's Yucatan Peninsula.

Steve Backshall searches for remains of the Mayan civilisation in the Yucatan, and discovers a flooded cavern filled with the remains of human sacrifice victims.