Lake Baikal

Lake Baikal is an ancient, massive lake in the mountainous Russian region of Siberia, north of the Mongolian border. Considered the deepest lake in the world, it's circled by a network of hiking paths called the Great Baikal Trail. The village of Listvyanka, on its western shoreline, is a popular starting point for summertime wildlife-spotting tours, plus wintertime ice-skating and dog sledding.