Changzhutan or Chang-Zhu-Tan, also Greater Changsha Metropolitan Region or Changsha-Zhuzhou-Xiangtan City Cluster (simplified Chinese: 长株潭城市群; traditional Chinese: 長株潭城市群; pinyin: Cháng-Zhū-Tán Chéngshì Qún) is a city cluster in Hunan province, China, consisting of the provincial capital, Changsha and two other prefecture-level cities: Xiangtan and Zhuzhou; it is the main heavily urbanized region of Hunan and covers an area of 28,087 km (10,844 sq mi).
Economist Intelligence Unit identified Chang-Zhu-Tan as one of China's 13 megalopolises in its 2012 report "Supersized Cities", with an estimated 2010 population of 8.3 million and 2009 GDP of 320 million Chinese yuan (CNY) Other sources put the population at 5.92 million.