On the tiny island of Slotsholmen in the center of Copenhagen, you'll find the Danish seat of government. Boasting more than 800 years of history, Christiansborg is the power base of the kingdom of Denmark and now home to the Parliament, the Prime Minister's Office, and the Supreme Court. Fans of the TV series Borgen will be familiar with the setting. Several wings are still used by the Royal household and much of this is open to the public. Bishop Absalon built fortifications of the city here in 1167, and visitors can see ruins of the bishop's castle, which was destroyed in the 14th century, as well as the medieval fortress.