Dunollie Castle was originally a 13th century enclosure fortress, founded by the Chiefs of the Clan MacDougall of Lorn. Overlooking Oban Bay, this rock promontory was the site of a late 7th-8th century structure of the kings of Dalriada. In the mid 15th century, John MacDougall founded the stone castle, when he diagonally flanked a square four storey tower house, on the north-east angle of a small square courtyard. The tower with its barrel-vaulted basement and second floor hall is crowned by traces of a parapet walk. A restored eastern gateway and a blocked northern postern with a zigzag passage, pierce the remaining high walls of the courtyard. On the west are the foundations and a high wall of a 16th century or later range and along the east wall is evidence of more internal buildings. There are also fragmental remains of an outer enclosure, that once encased the rest of the summit. 2 miles north-east is Dunstaffnage Castle.