Borgarvirki Fortress

Borgarvirki is the eroded core of an old volcano: tall hexagonal basalt columns standing in a natural ring of walls, ten to fifteen metres high, on a rise between the valleys of Víðidalur and Vatnsdalur in north-west Iceland. Iceland's settlers finished the ready-made citadel, walling the gaps between the columns and adding a gate and small dwellings inside; the sagas link it to the feuds of the settlement age. A short path and wooden staircase climb to the rim, where a viewfinder names the peaks.