Sonderborg Castle is a historic fortress located in Sonderborg, Denmark. Originally built in the 13th century, it has served various purposes over the years, including as a royal residence and military stronghold. The castle features a mix of architectural styles, reflecting its long history and numerous renovations. Today, Sonderborg Castle houses a museum that showcases local history and culture. Visitors can explore its beautiful gardens, impressive interiors, and exhibitions that highlight the region's heritage. The castle is a popular tourist destination, offering a glimpse into Denmark's past and its significance in European history.