Christiansborg Palace on Slotsholmen in central Copenhagen is the home of Denmark's three supreme powers: the executive power, the legislative power, and the judicial power. It is the only building in the world which is the home of all a nation's three supreme powers.
The palace now houses the Royal Reception Rooms, the Queen's Library, the audience chambers, the Sovereign in Council rooms, the Chapel, Parliament, the Supreme Court and the Prime Minister's Office.
Christiansborg Palace is owned by the Danish state, and is run by the Palaces and Properties Agency.
The palace today bears witness to three eras of Danish architecture, as the result of two serious fires. The first fire occurred in 1794 and the second in 1884. The main part of the current palace, built in 1928, is in the historicist Neo-baroque style. The chapel dates to the 1800s and is in a neoclassical style. The showgrounds date were built in the eighteenth century in a baroque style.
See more at http://en. wikipedia. org/wiki/Christiansborg_Castle