Season 4 - Episode Guide

Visits to the most remote, cold and inhospitable places on the planet to reveal great mysteries that have been frozen in time. Merging CGI re-creations, advanced scanning technology and scientific research, the series investigates the curiosities that have been lost for millennia, or never seen before.

Visits to the most remote, cold and inhospitable places on the planet to reveal great mysteries that have been frozen in time. Merging CGI re-creations, advanced scanning technology and scientific research, the series investigates the curiosities that have been lost for millennia, or never seen before.

The history of the woolly mammoth, revealing adaptations that helped the species evolve from its origin in the tropics to surviving in Siberia.

Visits to the most remote, cold and inhospitable places on the planet to reveal great mysteries that have been frozen in time. Merging CGI re-creations, advanced scanning technology and scientific research, the series investigates the curiosities that have been lost for millennia, or never seen before.

Visits to the most remote, cold and inhospitable places on the planet to reveal great mysteries that have been frozen in time.

The Patagonian ice dragon, which isn't actually a dragon but an insect that has adapted to life on the frozen glaciers of South America's Andes Mountains, the only bug that lives on the Patagonian ice fields. Scientists believe that their bodies contain natural antifreeze, which stops their blood from turning solid amidst the bitter cold.

Visits to the most remote, cold and inhospitable places on the planet to reveal great mysteries that have been frozen in time. Here, a Swiss fisherman uncovers ancient Celtic relics in Lake Neuchâtel, hinting at a violent Iron Age battle that happened around 225BCE.

The Siberian death mask, which was discovered in eastern Siberia in 1968 in a burial mound with cremated remains. It is a clay head sculpture of a young man that contains a ram's skull.

Great mysteries that were once frozen in time, here focusing on secrets now revealed of prehistoric warfare.

The lost legacy of the Donner Party, a group of nearly 90 emigrants who left Illinois in the spring of 1846, heading westward to California in covered wagons. Delayed by a multitude of mishaps, they spent the next winter snowbound in the Sierra Nevada, with some resorting to cannibalism to survive.