Nan Do or Al Som is an islet off the east coast of North Korea. It is white and barren. It lies about 11.3 miles east of Yujin Dan.
History
American whaleships cruised for right whales off the islet between 1849 and 1888. They called it White Rock. Some went ashore to collect bird's eggs.
References
Nan Do Wikipedia(Text) CC BY-SA