Koldinghus is a historic castle located in Kolding, Denmark. Originally built in the 13th century, it served as a royal residence and a strategic fortress. The castle has undergone several renovations and expansions over the centuries, reflecting various architectural styles. Today, Koldinghus is a museum that showcases Danish history and culture. Visitors can explore its impressive halls, exhibitions, and beautiful gardens. The castle also hosts events and activities, making it a popular destination for both locals and tourists.