source:clickhereAn ice hiker pauses in an ice cave on Lake Baikal, in eastern Siberia. With depths plummeting to 5,387 feet, Lake Baikal is the world's deepest lake-- and it holds more water than all the Great Lakes combined. In winter, it can freeze into ice 1-4 feet thick, and caves form curtains of ice like the ones seen in this photo.
