Daniel-Johnson Dam

One of the world's biggest dams that created one of the world's largest reservoirs surrounding one of the world's most massive craters which was caused by one of the largest meteorites to ever strike the Earth. So there.

While this massive concrete dam isn't quite big enough to be seen from space, the reservoir it created, one of Canada's largest, certainly can be. The reservoir itself surrounds Manicouagan Crater, which usually garners most of the attention paid to the area along with the meteorite that created it. However the colossal man-made dam (formerly named "Manic-5") is a sight to see in itself. The arched concrete buttresses go as high as 700 feet, and together the 14 buttresses are nearly three-quarters of a mile long. Before the dam was completed in 1968, the water surrounding Manicouagan Crater was actually two crescent-shaped lakes. However, once the dam came online these lakes connected to form an "annular" lake with an artificial island in the middle. 

Hydro Quebec runs seasonal tours of the dam which are conducted in French, but guides at the visitor center do speak English and can answer pretty much any question. The visitor center is filled with models, simulations, and great photos of the construction process. The Daniel-Johnson Dam is a terrific example of man reacting to the earth reacting to space.