The Konzerthaus Berlin is the most recent building on the Gendarmenmarkt. It was built by Karl Friedrich Schinkel in 1821 as the Schauspielhaus. It was based on the ruins of the National Theatre, which had been destroyed by fire in 1817. Parts of the building contain columns and some outside walls from the destroyed building. Like the other buildings on the square, it was also badly damaged during World War II. The reconstruction, finished in 1984, turned the theatre into a concert hall. Today, it is the home of the Konzerthausorchester Berlin.