3 Guanting Reservoir (File photo)

Guanting Reservoir in Hebei province is the first large reservoir built after the founding of People's Republic of China. As one of the main water sources of Beijing, Guanting Reservoir once served for flood control, irrigation and electricity generation.

Suffering from serious pollution in the 1980s and 1990s, the reservoir stopped providing drinking water to the city in 1997. After years of efforts, it was reused as a source of drinking water provision in 2007.

Now it is a good relaxation destination especially for Beijingers.