Koldinghus is a Danish royal castle in the town of Kolding on the south central part of the Jutland peninsula. The castle was founded in the 13th century and was expanded since with many functions ranging from fortress, royal residency, ruin, museum, and the location of numerous wartime negotiations.
The castle was founded by Christoffer I in 1268 but the oldest remaining part of buildings is the north side facing the castle lake originally built by king Christoffer III. The western side was later built by king Christian I. King Christian III built the south side and the small towers in the courtyard.