What is "vindobala"

Vindobala (Brytonnic Celtic : windo- fair, white, bala ?) was a Roman fort at the modern-day hamlet of Rudchester, Northumberland. It was the fourth fort on Hadrian's Wall, after Segedunum ( Wallsend), Pons Aelius (Newcastle) and Condercum (Benwell). It was situated about to the west of Condercum. The name Vindobala means “White Strength”. The site of the fort is bisected by the B6318 Military Road, which runs along the route of the wall at that point.