The Museum Island in the River Spree houses five museums built from 1830 to 1930 and is a UNESCO World Heritage site. Restoration and construction of a main entrance to all museums, as well as reconstruction of the Stadtschloss continues. Also on the island and next to the Lustgarten and palace is Berlin Cathedral, emperor William II's ambitious attempt to create a Protestant counterpart to St. Peter's Basilica in Rome. A large crypt houses the remains of some of the earlier Prussian royal family. St. Hedwig's Cathedral is Berlin's Roman Catholic cathedral.