破四旧
The damage peaked during the Cultural Revolution. In 1966, the Hall of Worshipping Ancestors was modified and some artifacts destroyed for an exhibition of revolutionary mud sculptures. However, further destruction was prevented when Premier Zhou Enlai intervened by sending an army battalion to guard the city. These troops also prevented ransacking by the Red Guards who were swept up in the storm to demolish the "Four Olds". From 1966 to 1971, all gates to the Forbidden City were sealed, saving it from more destruction.