Dumbarton Rock enters written history as Alcluith, the seat of Ceretic, the British King of Strathclyde.
It was the capital of the Kingdom of Strathclyde until 1018, when it was absorbed into Scotland by Malcolm II, and by 1222 a castle had been built on it, ending its time as a fort, but continuing its use as defensive site.
OS Map for Dumbarton Rock
OS Explorer map 347/OL38
Buy from Ordnance Survey
Alternative names for Dumbarton Rock