Opera House Dortmund opened in 1966 and is the second opera house to exist in Dortmund, the first one having been built in 1904, but it was destroyed during World War I. The 1966 opera house was designed by architects Heinrich Rosskotten and Edgar Tritthart. The design separates the functions of the stage and technical areas in the Buhnenhaus (stage house), which is dominated by straight lines, from the auditorium under a thin-shell structure roof.