This original High Medieval, Late Medieval and Early Modern castle site was on the southern bank of the River Farset (which now flows beneath High Street), being located on a sliver of land that was bounded by the Farset to the north and the River Owenvara (Blackstaff River) to the south. Both the River Farset and the River Owenvara (Irish: "Abhainn Bheara", meaning 'River of the Staff', usually known nowadays in English as the Blackstaff River) emptied into the River Lagan just to the east of this castle site.