While Lake Baikal was known as the “North Sea” in historical Chinese texts, it was situated in the then Xionu territory and very little was known about Lake Baikal until the Trans-Siberian railway was built between 1896 and 1902. The scenic loop encircling Lake Baikal needed 200 bridges and 33 tunnels. As this railway was being built, a large hydrogeographical expedition headed by F.K. Drizhenko produced the first detailed atlas of the contours of Baikal’s depths. The atlas demonstrated that Lake Baikal has more water than all of North America’s Great Lakes combined — 23,600 cubic kilometers (5,662.4 cu mi), about one fifth of the total fresh water on the earth. However, in surface area, it is exceeded by the much shallower Great Lakes Superior, Huron and Michigan in North America, as well as by the relatively shallow Lake Victoria in East Africa. Known as the “Galápagos of Russia”, its age and isolation have produced some of the world’s richest and most unusual freshwater fauna, which is of exceptional value to evolutionary science.