Introduction to Longhai Apartment: Longhai Apartment was built in 1925 and was invested and built by Lei Heting, the battalion commander of Baibaoshan, the governor of Haizhou, the Beiyang warlord. The architectural style of the apartment is a combination of Chinese and Western styles, with a layout of "front yard and back well". The front yard is an antique two-story building used as a guest room, and the back well is a bungalow for living, covering an area of ​​250 square meters and a construction area of ​​410 square meters. In March 1938, Wan Yi, the commander of the 667th Regiment of the 112th Division of the 57th Army of the Northeast Army stationed in Lianyungang, was introduced by Zhang Wenhai and Gu Mu, the special commissioners of the Yangtze River Bureau of the Communist Party of China, and honorably joined the party in Longhai Apartment and became a secret member of the Communist Party of China. Members of the 112th Division Underground Working Committee Zhang Wenhai, Gu Mu, Li Xin and others left glorious combat footprints in Longhai Apartment.