The oldest and deepest lake in the world. A beautiful, crystal clear lake 636 km long by 25-80 km wide with vertical visibility so good it is said some people experience vertigo looking into it. Ices over in the winter and is glorious in the summer. More info at: http://www.bww.irk.ru/ and http://www.livinglakes.org/baikal/ and http://en.wikipedia.org/wiki/Lake_Baikal