One of Zealand's most important Viking Age sites, this large ring fortress dates to AD 980. It is essentially a perfectly circular raised earthwork, 300m beyond a museum that explains the context, though if you arrive outside the museum's opening hours, you can still visit the main site. Between the two you'll pass a very atmospheric, full-sized Viking wooden longhouse reconstruction.

On return, look to the left of the museum to find a mini 'village' of six thatch- and turf-roofed Viking building mock-ups. A week's festival in mid-July brings this site to life with costumed characters, craftsmen at work and various activities for kids.

Walking up onto the circular rampart you can readily grasp the strikingly precise geometric design of the fortress. Its grassy banks are 17m wide and 6m high, and were originally topped by a wooden palisade. The banks protect a central space where two streets once divided the circle into quarters. Each quarter contained a courtyard with four wooden longhouses, which have long since decayed away, but the post holes and gable ends have been identified and filled with cement to show the outlines of their foundations.

Sheep graze the site impervious to its history and the trickle of visitors, imbuing the scene with a timeless, peaceful aura.