Bårby Borg was an ancient hill fortification. It was built in two periods, first in the age of migrations and later in the Middle Ages. Bårby Borg is the only hill fort in Öland where a natural steep scarp was used as part of the fortification. The other sides were protected by stone wall. The diameter was approximately 150 meters. Archaeologists have found a gold coin from the ruins made in Byzantine Empire in the 6th century AD.
References:Doune Castle was originally built in the thirteenth century, then probably damaged in the Scottish Wars of Independence, before being rebuilt in its present form in the late 14th century by Robert Stewart, Duke of Albany (c. 1340–1420), the son of King Robert II of Scots, and Regent of Scotland from 1388 until his death. Duke Robert"s stronghold has survived relatively unchanged and complete, and the whole castle was traditionally thought of as the result of a single period of construction at this time. The castle passed to the crown in 1425, when Albany"s son was executed, and was used as a royal hunting lodge and dower house.
In the later 16th century, Doune became the property of the Earls of Moray. The castle saw military action during the Wars of the Three Kingdoms and Glencairn"s rising in the mid-17th century, and during the Jacobite risings of the late 17th century and 18th century.