This photo of a Medieval staircase from Ballyhannon Castle in Ireland (c. 1490) shows a typical construction: the staircases were usually spiralled clockwise moving up, so that defenders could take the advantage using the center beam for protection, while attackers had a harder time using their sword-arms without exposing their bodies. An exception that proves the rule is Ferniehirst castle, an originally 15th-century structure with a counter-clockwise staircase that belonged to the Kerr family clan in Scotland. It is on record that the Kerrs had many left-handed members, and thus built their castle stairways with this in mind.
