When it comes to breaking records, Lake Baikal is hard to beat. This massive high-altitude rift lake in Siberia is the oldest and deepest lake in the world—reaching a maximum depth of 1,642 meters and an estimated 25 million years of age. Baikal is also the largest freshwater lake in the world—over 20 percent of the world's fresh water is in this lake.
Although Lake Baikal is considered one of the clearest lakes in the world, this is particularly noticeable in winter, where, in some areas, it's possible to see up to 40 meters down into the water—even though much of the lake's surface freezes over for up to five months of the year.
For about a month around August, the lake's water temperature can reach around 16 degrees Celsius, making it suitable for quick dips or short swims.
In summer, Lake Baikal is a famous destination for kayaking, boat cruises, and island hopping to discover shorelines and beaches. In winter, when the lake freezes over, visitors can cross-country ski across sections of it and visit the frozen Tazheran Steppes caves.