Steve returns to paddle the uncharted waters of the Kronotsky river in the far east of Russia, evading Russian grizzlies along the way.

Steve joins forces with ropes expert Aldo Kane and Saudi Arabian geologists Mahmoud Al-Shanti and Hala Alwagdani to search for the longest lava tube in Arabia.

Steve and the team head to remotest Kyrgyzstan in search of snow leopards - if the team can find evidence of the endangered big cat, they could protect the environment it lives in.

Steve heads to the Moukalaba Doudou national park in Gabon to be guided through its natural scenery and to search for undiscovered chimps.

Steve teams up with shark scientist Mauricio Hoyos to discover where shark mothers give birth and to protect a new generation of these ocean giants in the Eastern Pacific.

Steve takes a look at the best unseen footage of season 2.