In recent years Lake Baikal, the deepest freshwater lake, has been paid much attention to because of an extreme sport. Each March, about 150 people sign up for the Baikal Lake Marathon. They come to explore the lake's extraordinary beauty and challenge themselves in unpredictable conditions. And in March, the ice is a meterthick and very hard. Runners cross the frozen surface, finishing on the western side of the lake. Known as the "blue eye ofSiberia" ,the lake has clear water. When seen from above, runners on the ice look as if they were jogging through space. The landscape might be beautiful but it is a severe test. Runners say the cold climate is what draws them.