The largest province of the South located 685 km from Bangkok is Surat Thani the province with a name that literally means'City of the Good People'. A former capital of the Srivijaya Empire, the province covers an area of approximately 12,891 sq km. Surat Thani Province borders the Gulf of Thailand to the north and east, Chumphon Province to the north, Nakhon Si Thammarat and Krabi Provinces to the south, Phang-Nga and Ranong Provinces to the west and Nakhon Si Thammarat Province to the east.
High plateaus and forested mountains are located to the west of the province, while there are low basins in the center and along the eastern coast. This topography has created 14 river basins including Tapee, Pum Duang, Tha Thong, Tha Krajai, Chaiya, Tha Chang which are the most important basins. All rivers in Surat Thani flow east of the province to the Gulf of Thailand.