Kastellet

Kastellet stands as one of Northern Europe's finest preserved star-shaped fortifications, built between 1662 and 1665 under King Frederik III and designed by Dutch military engineer Henrik Rüse. Originally named Citadel Frederikshavn, the fortress features a distinctive five-pointed star design with bastions and an impressive moat system, visible from above. The site houses several historically significant structures including Kastelskirken, a functioning mill, and the commandant's residence alongside World War II bunkers. Today Kastellet functions uniquely as both an active military barracks and public green space, free to enter daily from 6:00 AM with designated paths and rampart walks available for exploration, hosting joggers and history enthusiasts alike.