Are all Hunan test sites in Changsha?

Not all of them. There are test sites in Changsha, Hengyang, Xiangtan, Yueyang, Changde and Chenzhou. The specific test sites should be based on the test sites on the admission ticket, so the test sites in Hunan are not all in Changsha. Hunan Province, referred to as "Xiang" for short, is the provincial administrative region of People's Republic of China (PRC), with Changsha as the capital.