Around the year 980, Harald Bluetooth, king of the Danes, built a ring of fortresses across his kingdom, and Fyrkat is the best-preserved of them. It is a perfect circle of earth and timber rampart about 120 metres across, with four gates at the compass points and streets crossing in the middle, and inside the ring, sixteen longhouses arranged in groups of four around a square. Tree-ring dating of the timbers points to the early 980s, and the neat plan and the way it echoes the other ring forts at Trelleborg and Aggersborg suggest a single royal design. Why the forts were built is still argued over, though they probably combined military, administrative and royal power at a time when Harald was uniting Denmark and bringing in Christianity.
The site lies on a hill above the Onsild river just outside Hobro, a town of about 11,000 people at the head of the Mariager Fjord. A reconstructed longhouse stands inside the ring, and the museum shows finds from the dig, among them the grave of a woman who may have been a seeress, buried with a staff and seeds of henbane. The ramparts are low now and covered in grass, and the best way to understand the plan is to walk the circle and follow the lines of the houses marked in the turf.
Getting here is easy. The roads of eastern Jutland are gentle, with rolling fields, hedged lanes and beech woods, and the speed limits are strictly enforced by cameras. Wind can be strong near the coast, and showers pass quickly, so take a light waterproof. To the south lie the Rold Skov forest and the hills at Rebild, which are among the most pleasant places to ride in the region, with bends that rise and fall through heather and trees.
Hobro has fuel stations, supermarkets and cafés, and the harbour on the fjord is a good place for a coffee. The nearby town of Mariager, with its cobbled lanes and roses on the cottage walls, is worth a detour. Try a smørrebrød or a hot dog from a roadside kiosk, a Danish institution. Spring and early summer, with long light evenings, are good times to visit, and the site is quiet on weekdays.