Gamleborg

[2] Around 1100, significant alterations were made and it was reinforced, but it was abandoned soon afterwards in favour of the fortification of Lilleborg, roughly 700 metres (2,300 ft) to the northeast.

[1] Its builder is unknown, but an account of the Baltic Sea travels of Wulfstan of Hedeby in 890 tells us that Bornholm already had its own king at the time.

[5] Excavations in the 1950s showed the fortifications originated in the Viking period although there is evidence the site was used as a hideout in the Iron Age.

Part of the wall, built of rocks and boulders set in clay, is still in good condition, and the outline of the fort is still remarkably clear given its age.

[9] The defences first consisted of huge ramparts built of large boulders, consolidated with earth and clay.