 This 11th century work generally built upon the earlier fort, except that stone interior cells were replaced with timber structures, and a second outer defensive wall was erected.Presently the fort is used as a tourist site for visitors to Öland to experience a fortification for this region.A museum within the castle walls displays a few of the large number (26 000) of artefacts retrieved by the National Heritage Board during the major decade long excavation ending in 1974.