Cardross Castle The site of Cardross Castle is unknown, but is thought to be near Castlehill in the W of Dumbarton, which is within Cardross parish, 2½ miles (4 km) east southeast of the settlement of Cardross on the northern shore of the River Clyde. This is castle or manor house where Robert the Bruce died here from leprosy in 1329. Traditionally located on Castle Hill, which is now within the Cunninghame Graham Memorial Park, this now seems unlikely as records suggest that the King kept boats near his castle, so a location closer to the River Leven is supposed, perhaps to the east of Dalmoak Farm at the former farmstead of Mains of Cardross.