Rosenborg Castle is a historic royal residence located in Copenhagen, Denmark. Built in the early 17th century by King Christian IV, the castle showcases a beautiful Renaissance architectural style. It originally served as a summer home for the Danish royal family and is now a museum. Today, Rosenborg Castle houses the Crown Jewels and royal regalia of Denmark. Visitors can explore its ornate rooms, lush gardens, and impressive collections, providing a glimpse into the opulent lifestyle of the Danish monarchy throughout history. The castle is a popular tourist attraction, reflecting Denmark's rich cultural heritage.