The Alte Oper (Old Opera House) on Opernplatz in Frankfurt am Main is not only a world-famous concert and event venue, but also one of the most important architectural sights of the Main metropolis. The characteristic design of the opera house consists of two structures that are nested inside each other – a core building containing the staircase, auditorium and stage, and a shell building that forms the façade of the building with its striking balustrade. During an air raid in 1944, the Alte Oper was largely destroyed and left in ruins until 1976. During this time, the Frankfurt Opera had its venue on Theaterplatz. The elaborate restoration was then completed in 1981.