There are two theories about the origin of the second part of the name Saar"brücken". The most popular theory states that the historical name of the town, "Sarabrucca", derived from the Celtic word ' ("hill", or "rock", "big stone"), which became ' (which means "rock" or "boulder") in High German. The castle of "Sarabrucca" was located on a large rock by the name of "Saarbrocken" overlooking the river Saar. A minority opinion holds that the historical name of the town, "Sarabrucca", derived from the Old High German word "Brucca" , meaning "bridge", or more precisely a corduroy road, which was also used in fords. Next to the castle, there was a ford allowing land-traffic to cross the Saar.