Visborg was a medieval fortress at the southern tip of Visby, built in the 15th century and destroyed in 1679. What remains is substantial: long stretches of the outer walls, the bases of several towers, and earthworks that give a clear sense of the original layout. The ruins sit at the harbour's edge outside the main city wall, and the walk from Söderport gate through the ruins and along the seawall is one of the better routes in Visby.
The site is freely accessible and mostly unexcavated. In summer the grass around the walls is thick and the setting is quietly dramatic — the sea to one side, the medieval wall to the other.