Wall Mile 20

Hadrian's Wall stretches from the east to west coast of England and was an important frontier of the Roman Empire. Building of the wall began in AD 122 and took six years to complete it’s 84 mile (80 Roman mile) length. Soldiers were garrisoned along the line of the wall in large forts, smaller milecastles, and intervening turrets. The Vallum, a large ditch with mounds on either side, ran along the south side of the wall, protecting the rear of the frontier. Hadrian's Wall was designated as a World Heritage Site in 1987.

Wall Mile 20:

• Milecastle 20 (Halton Shields)
• Turret 20A (Carr Hill)
• Turret 20B (Downhill East)

Scheduled Monument (#1010623): Hadrian's Wall and vallum between Sunnybrae at Halton Shields and Haltonchesters Roman fort in wall miles 20 and 21

The monument includes the section of Hadrian's Wall, vallum and associated features between Sunnybrae at Halton Shields in the east and the field boundary to the immediate east of Haltonchesters Roman fort in the west. This section of the corridor follows an east-west ridge with slopes down to the north and south. Hadrian's Wall survives as a buried feature beneath the B6318 road throughout most of this section.

Hadrian's Wall survives as a buried feature beneath the B6318 road throughout most of this section. At Halton Shields the alignment of the Wall suggests that it runs below the houses and gardens, however, as there are no upstanding remains there, this area is not included in the scheduling. At Down Hill the Wall survives as a discontinuous bank of rubble, 3m wide and 0.4m high, within dense woodland. Quarrying has mutilated much of the east end of this bank. As with the Wall the wall ditch is in part overlain by the B6318, but in Down Hill Wood it is visible intermittently in the dense woodland up to a maximum of 3m deep. However, it too has been destroyed by quarrying in places. Elsewhere the ditch is traceable as an earthwork in the fields to the north of the B6318.

Milecastle 20 is situated immediately north of Sunnybrae at Halton Shields. It was located and partly examined in 1935 and was found to have `type III' gateways, which is a construction style usually associated with the work of the twentieth legion. During 1992 a 5.5m length of the south wall was exposed which measured 2.6m across, showing that the remains are well preserved under the existing house and garden.

Turret 20a has also yet to be located, but also on the basis of the usual spacing it would be expected to lie about 70m east of the properties at Carr Hill.

Turret 20b was located in 1935 by Hepple about 130m east of Down Hill Wood. The turret survives as a buried feature below the B6318 road.

The course of the Roman road known as the Military Way, which ran along the corridor between the Wall and vallum linking the turrets, milecastles and forts, survives intermittently throughout this section of the corridor. An excavation undertaken in 1893 revealed that it occupies the north berm of the vallum until the vallum swings south to the east of Down Hill where it resumes a course between the Wall and vallum. There are no upstanding remains west of Down Hill in this section.

The vallum runs parallel with the Wall to Down Hill where it takes a dog-leg to avoid the bedrock close to the surface. It is visible intermittently throughout this section of the corridor. It is best preserved to the south of Down Hill where the vallum ditch has a maximum depth of 2.7m and the north and south mounds reach a height of 1.5m and 1m respectively. Clear traces of crossings survive which are best preserved in the north mound.