Three Gorges Dam, in Hubei Province, China, will be the world's largest dam and largest concrete structure and create the largest lake. The dam will be built across the 3 Gorges section of the Yangtze River. It will be a 610-foot high wall running about 1.3 miles from bank to bank. Requiring 12 years and tens of thousands of workers to complete, the dam will cost $29 billion, and will create a 370 mile long lake, a distance equal to nearly half the length of California, that will be visible from Earth orbit.