Warren's Opera House, in the Warren Building at 511 2nd St. in Friend, was built in 1885–86 for grain merchant Joshua Warren and listed on the National Register of Historic Places in 1988. The upstairs opera house closed about 1930. The Friend Historical Society has replaced the roof and repaired the foundation and brick, and work on an accessible stair and elevator began in 2025; university opera students have performed there. The ground floor has the San Carlo Room event space.