Bahe Academy Guangzhou

Formerly a guild hall for Cantonese opera practitioners, Bahe Academy opened in 1889 to provide lodging and other services to opera troupes. It now serves as a meeting place for retired artists, and isn't open to the public, though you can sometimes sneak a peek inside. Check out the the original 3m-tall wooden doors from 1889, the only bit that survived a bombing raid by the Japanese in 1937. They were supposedly used during the Great Leap Forward as parking planks for heavy vehicles, and clearly survived that as well.