The name might reflect the town's location at the terminus of the long ridge of land running along the east side of the river. However, this ridge is not actually very prominent and few visitors would perceive Penkridge as a hill town. Modern toponymists have become convinced that the hill in question was more likely a tumulus—prominent in pre-Roman and Roman times, and perhaps much later. Brewer comments that "none is evident in the locality". However, Margaret Gelling, predisposed to find direct evidence for toponyms in the local landscape, has proposed a precise location for the mound, now destroyed by ploughing, that gave both the town and, ultimately, the river their names. This was a tumulus at Rowley Hill Farm, Ordnance Survey reference GR90251180, approximately , which was still prominent in the 18th century and still discernible in the early 20th. It would have directly overlooked the outlying Roman camp, across the Penk and just north of Pennocrucium on Watling Street, the remains of which are clearly visible in satellite photographs. Certainly, it makes more sense to look for the hill in question in the immediate vicinity of the ancient settlement than that of the modern town, which is well to the north of it. The Rowley Hill tumulus is well documented, and was clearly an extremely important landmark for several millennia.