Martyr's Cemetry (烈士墓)+Zhazidong (渣滓洞)+Bai's Mansion (白公馆), three sites in a row in the mid-level of Gele Mt.(歌乐山), all free to public -- very politicized, NOT quite interesting for foreigners, especially from western countries
Martyr's Cemetry (烈士墓): a shrine in memory of the communist martyrs who were killed before Chongqing's was "liberated" from Nationalist Gov in 1940s.
Zhazidong (渣滓洞): the prison founded by Nationalist to keep communists "rebels", many inhumane torture and prosecution utilities on display
Bai's Mansion (白公馆): the custodian utility used by Nationalists to jail political enemies, and used to accommodate U.S alliances during WWII.
*Nationalist Party was founded by Sun Yat-sen, and succeeded by Chiang Kai-shek who founded modern Taiwan regime.
*Chongqing is the place where the peacetalk about formality of ruling and coalition between Nationalist and Communist Party broke, and the Cvil War ensued (1945-1949).