Dashan Island is located 28-nautical-mile (52 km) from Lianyungang, and it belongs to the Qiansandao Town of Lianyungang city, Jiangsu province, China. The island has an area of 0.115 km², and is one of the islands in the Qiansan Islands.
Dashan Island is a baseline point of the Chinese territorial sea.
In 2006, PLA erected the Territorial sea steles on Dashan Island.
- Declaration of the Government of the People's Republic of China on the baselines of the territorial sea(May15th, 1996)