`Yiyuan` is located on Sixin Road, Yuzhong District, Chongqing City. It was built in 1937. It is half hidden on a small hill. It used to be the mansion of Song Ziwen, a senior official of the Nationalist Government during the war.
Song Ziwen December 4, 1894-April 26, 1971, a politician, diplomat, and financier during the Republic of China, was born in Wenchang, Hainan. Song Ziwen is the son of Song Jiashu, and his brothers and sisters are Song Qingling, Song Meiling, Song Ailing, Song Ziliang and Song Zian.
The house in `Yiyuan` has three floors. The exterior of the building is made of stone. There are balconies of different sizes on the second and third floors. It is a Gothic-style brick and stone castle. During the Anti-Japanese War, it served as the residence of Song Ziwen, then the Minister of Foreign Affairs and Premier of the National Government, and Marshall, the special envoy of the US President, also lived here during the military negotiations between the Kuomintang and the Communist Party. After the liberation of Chongqing, `Yiyuan` was once used as a government agency guest house, and was announced as a municipal cultural relic protection unit by the Chongqing Municipal People`s Government in March 1992.