Valdemar's Castle (Danish: Valdemars Slot) is a manor house situated on the island of Tåsinge near Svendborg in southern Denmark.^[1]

Valdemar's Castle was commissioned by King Christian IV (1588–1648) and built between 1639 and 1644 under the plans designed by architect Hans van Steenwinckel d.y. (1587–1639). It was not a fortification, but rather a large manor house. King Christian was well known for his interest in building. Tåsinge, the island where Christian planned to have Valdermar's Slot built, belonged to his mother in law Ellen Marsvin. He intended the new mansion should become the home of his son Valdemar Christian (1622–1656) whose mother was Kirstine Munk. Valdemar Christian never occupied the manor but was killed during a battle in Poland in 1656. In 1678, the naval hero, Admiral Niels Juel (1629–1697) was given title to the castle and the land on Tåsinge after his victory over Sweden in the Battle of Køge. The estate was transferred to him as payment for the Swedish ships captured in the battle.^[2][3]

The previous owner, Baron Niels Krabbe Iuel-Brockdorff, who is 10th generation of the Juel family, took over his childhood home from his father in 1971 and lived in the castle with his wife and family until his death on January 20, 2017. Valdemar's Slot has been open to the public since 1974. The mansion is open from May to October and on public holidays. It features a large chapel, a toy museum, the Iuel-Brockdorff family's big game trophy collection and a local maritime museum. As it stands close by the shore, many visitors make the trip from Svendborg using the veteran ferry Helge.

• Gate
• Tea pavilion
• Garden behind church
• Drawing from 1872