Slotsholmen

Slotsholmen (lit. translation, "the castle islet") is a small island in Copenhagen Harbour, Denmark (location: coord|55|40|30.9|N|12|34|50|E|region:DK_type:landmark), also known in English as Castle Island. It was the site of the first castle in Copenhagen, Absalon's Castle. Subsequently Copenhagen Castle was built on the same site.

Today Christiansborg Castle, home of Denmark's Parliament ("Folketing"), the Danish Royal Library (with "The Black Diamond"), historic building Børsen, museums, a church, The Danish National Archives and other official institutions are located on the island.

Visitors to Christiansborg Castle can tour the ruins of the two older buildings on the site.