Kastellet

A star fortress from 1664

Kastellet is one of the best-preserved star fortresses in Northern Europe. Its origins go back to 1626, when the Sankt Anna Sconce was built under Christian IV. After the Swedish siege during the Second Northern War (1658–1660), Dutch fortress engineer Henrik Ruse rebuilt the site entirely between 1662 and 1665 as the Citadellet Frederikshavn. The first soldiers moved into Kastellet on 28 October 1664.

The layout is a pentagon with five bastions, named after the King, Queen, Count, Princess and Prince. In front of them lie outworks such as ravelins and counterguards, plus the water-filled moats. The star shape is easiest to make out from the air – on foot, it reveals itself as you walk along the ramparts.

What to expect on site

Inside the ramparts, the red barracks buildings, the commandant's house and a number of historic structures are arranged symmetrically. Free to enter or accessible on guided tours are, among others:

• Kastelskirken, a Baroque-style church built in 1703/04 and consecrated on 26 November 1704, still an active parish church today
• the Kastelsmølle, an octagonal Dutch gallery windmill from 1847 with five storeys – Copenhagen's only working windmill
• the collection run by Kastellets Venner with guided tours, the Life Guards Museum (Livjægermuseet), a Second World War bunker, the Powder Tower (Krudttårnet) and the Arresthuset (former guardhouse)
• the monument to Denmark's international military missions

Worth knowing: Kastellet is an active barracks. Not all buildings are open to the public, and walking on the grass inside the ramparts is not allowed. The windmill has no regular visiting hours – tours are held on Danish Mill Day, the third Sunday in June.

A green park for walking

Outside the areas used by the military, Kastellet is above all a quiet, well-kept park. The ramparts are ideal for walking, jogging and picnicking, with a path circling the fortress that offers water views throughout. There's a canteen on site, and public toilets can be found near the outer gates.

The ramparts are surfaced with compacted gravel and are largely accessible by wheelchair or pushchair; a few paths – such as the one to the windmill – are more uneven and partly cobbled, though ramps are provided there. Allow 45 to 60 minutes for a relaxed walk, longer if you bring a picnic.

Getting there & combining your visit

Kastellet sits at the northern end of the Langelinie waterfront promenade, right next to The Little Mermaid. It's about a 15-minute walk from Amalienborg Palace, and around 30 minutes from Nyhavn. Østerport station is at the western entrance, and bus routes such as 23 and 1A also stop nearby.

If you're heading to The Little Mermaid, the nicest route is across the green ramparts – a quiet, scenic alternative to the busy harbourfront path. It combines well with the changing of the guard at Amalienborg at noon and the nearby Marble Church. To go deeper into the history of the Danish crown, visit Rosenborg Castle.