stone plaque with Chinese characters, indicating that the "Beihai and Tuancheng" site is designated as a national key cultural relics protection unit

stone plaque with Chinese characters, indicating that the "Beihai and Tuancheng" site is designated as a national key cultural relics protection unit. The announcement was made by the State Council of the People's Republic of China on March 4, 1961. The plaque was erected by the Beijing Municipal Bureau of Cultural Relics Affairs in July 1981.