The Residence Castle (Residenzschloss) in Detmold originated from a medieval fortress. This was incorporated into the current Renaissance palace structure. It is surrounded on three sides by water. The castle was built by the counts of Lippe, whose descendants still own the it today. Visitors can enter the castle and take tours to marvel at the various state rooms and halls, which mainly date from the 18th and 19th centuries, although there are older items such as the Brussels tapestries from the 17th century on display.