Lake Baikal

Lake Baikal, located in Siberia, Russia, is the world's deepest and oldest freshwater lake, reaching depths of 1,642 meters (5,387 feet). Formed 25 million years ago, this UNESCO World Heritage Site holds 20% of Earth's unfrozen freshwater—more than all North American Great Lakes combined. Known as the "Galápagos of Russia," it hosts 1,700+ unique species, including the endangered Baikal seal. Its crystal-clear waters reveal visibility up to 40 meters (130 feet) in winter. Surrounded by mountains and taiga forests, Baikal remains one of the planet's most pristine and scientifically significant ecosystems, freezing into mesmerizing turquoise ice during winter.