The castle was built in the early 17th century by King Christian IV and is surrounded by the King’s Garden, which is a park. Apparently this castle was initially built as a summer home, but it was Christian IV’s favorite. In fact, it was used as a Royal residence until 1710, after which it was only used twice as a royal residence during emergencies when the other castles burnt down.
It holds a lot of artifacts, especially the Crown Jewels of the Royal family, and it is beautiful in its own way, but I found the interior of it to be really dark, and as such, it wasn’t my favorite castle in Copenhagen.