冬季的北京什刹海（后海）风景。

ai (Houhai) is a historical and cultural tourism scenic area and a historical and cultural protection zone in Beijing. Located in Xicheng District of the city center, adjacent to the central axis of Beijing. The water area is 336000 square meters, connected to the Zhongnanhai water area. It is an open scenic spot with an open water surface in the inner city of Beijing, and also the largest and most well preserved historical district in Beijing. It occupies a unique position in the history of Beijing's urban planning and construction.