Tour Scotland travel video of Dumbarton Castle. This Scottish castle has the longest recorded history of any stronghold in Great Britain. It is located on a plug of volcanic basalt known as Dumbarton Rock. At least as far back as the Iron Age, this has been the site of a strategically important settlement. Its early residents were known to have traded with the Romans. The presence of a settlement is first recorded in a letter Saint Patrick wrote to King Ceretic of Alt Clut in the late 5th century. Mary Queen of Scots sailed to France from here as a child in 1548.
