Aerial view of car crossing over the frozen surface of Lake Baikal, Russia

© Amazing Aerial Agency/Offse

The Pearl of Siberia

Lake Baikal is a record-holding wonder: It’s the world’s oldest (25 million years), deepest (over 5,000ft in some parts) and largest freshwater lake (containing more than 20 per cent of the Earth’s fresh surface water by volume). Baikal lies in the deepest continental rift valley on Earth, and because the rift is geologically active, the tectonic plates continue to move farther apart.

Fair-weather tourists visit the 'Pearl of Siberia' in warmer months, but the brave and hearty show up here in January when the lake surface freezes over. The ice makes an excellent playground for winter athletes competing in everything from skating marathons to the Baikal Ice Golf Tournament. And when the frozen expanse is at its thickest, an ice road opens between the mainland and Olkhon Island, pictured here, allowing people to drive across turquoise ice so clear, it's transparent to depths of 100ft.