Tonkin (Đông Kinh in Vietnamese), also spelle Tongkin or Tongking, is the northernmost part of Vietnam, south of China's Yunnan and Guangxi Provinces, east of northern Laos, and west of the Gulf of Tonkin. Locally, it is known as Bắc Kỳ, meaning "Northern Region". Located on the fertile delta of the Red River, Tonkin is rich in rice production.