Dumbarton Castle

The impressive fortress built around a rock, defending the upper reaches of the Clyde

It's a hard road in. Once you're past the curtain wall, up through the entrance to the Spur Battery, up to the main building (the Governor's House) and then round the back and up the steps to the smaller building guarding the Portcullis Arch in the cleft in the rock. Hard to attack, easy to defend.

The small park on the river frontage is next to Dumbarton Bowling Club.