The Hangzhou-Jiaxing-Huzhou Plain, or Hangjiahu Plain () is the largest plain in Zhejiang province, and is an integral part of the Yangtze Delta. Comprising an area of , it is bound by Lake Tai to the north, the Qiantang River / Hangzhou Bay to the south, and Tianmu Mountain to the west. It includes all of the prefecture-level city of Jiaxing, most of Huzhou, and the northeastern part of Hangzhou.