The Bayreuth Festspielhausis an opera house north of Bayreuth, Germany, dedicated principally to the performance of operas by the 19th-century German composer Richard Wagner.
It is the exclusive venue for the annual Bayreuth Festival, for which it was specifically conceived and built. The design was adapted by Wagner, without the architect's permission, from an unrealised project by Gottfried Semper for an opera house in Munich, and built under Wagner's supervision. Its construction was funded principally by King Ludwig II of Bavaria. The foundation stone was laid on 22 May 1872 (Wagner's birthday). The building was first opened for the premiere of the complete four-opera cycle of Der Ring des Nibelungen (The Ring of the Nibelung), from August 13, 1876 to August 17, 1876.