Lake Baikal is located in southern Siberia in Russia and is known as the deepest lake in the world, with a depth of approximately 1,642 meters or 5,387 feet. It is also known as the oldest freshwater lake in the world, with an age of approximately 25-30 million years. It also contains the most water of any lake in the world, with approximately 20% of the Earth's unfrozen surface water.