West Lake was originally a lagoon, but in the eighth century the governor of Hangzhou had it dredged, and later a dyke was built that cut it off from the Qiantang River completely. The resulting lake is about 3 km long and 3 km wide, with two causeways dividing the lake into sections.

The lake has several islands. The largest is Gu Hill, which is the site of the Zhejiang Provincial Museum. The Baidi Causeway links the island to the mainland.

The smaller island in the middle of the lake is known as Lesser Yingzhou Island, where you can view the three small towers in the water on the south side of the island. These are often referred to as Three Pools Mirroring the Moon. Red Carp Pond is also worth visiting as it is home to several thousand red carp.