Slotsholmen is an island, although you will hardly notice that, in the heart of historic and political Copenhagen. Slotsholmen is home to Christiansborg Palace, once the residence of the royal Danish family. Today the palace houses the Danish parliament and Supreme Court. And underneath is the very foundation of Copenhagen; the ruins of Bishop Absalon's Castle. The museums on Slotsholmen include The Royal Library, The National Archives, The Royal Arsenal Museum, The Royal Stables, The Theatre Museum, Thorvaldsens Museum, The Danish Jewish Museum and The Lapidarium of Kings.