Once established in an area, the Romans built roads. While the scale of these varied depending on the traffic, and while roads in high-status locations might be better finished, they all shared the same broad design. This consisted of a strip of land, perhaps 20 or 25 yards across, bounded by drainage ditches. In the centre of this strip was the road itself, a well-drained set of layers of earth and hard-core ten or even 15 yards wide. Often slightly domed and bounded by a kerb, this was known as the agger; up to three feet high, in some cases it was paved and then covered with compacted finer material. Surviving paved roads are rare in this country and some roads that were once considered Roman have turned out to be post-medieval turnpikes, but substantial stretches of paving have been uncovered near Holystone, just south of Alwinton, on the road that linked Dere Street with the main road running further east between Corbridge and Tweedmouth.