Milecastle 50, one of the milecastle

Milecastle

A milecastle was a small fort , a rectangular fortification built during the period of the Roman Empire. They were placed at intervals of approximately one Roman mile along several major frontiers, for example Hadrian's Wall in Great Britain , hence the name.Along Hadrian's Wall, milecastles were...

s on Hadrian's Wall

Hadrian's Wall

Hadrian's Wall was a defensive fortification in Roman Britain. Begun in AD 122, during the rule of emperor Hadrian, it was the first of two fortifications built across Great Britain, the second being the Antonine Wall, lesser known of the two because its physical remains are less evident today.The...

, is situated to the west of Birdoswald fort

Castra

The Latin word castra, with its singular castrum, was used by the ancient Romans to mean buildings or plots of land reserved to or constructed for use as a military defensive position. The word appears in both Oscan and Umbrian as well as in Latin. It may have descended from Indo-European to Italic...

 (OS grid reference

British national grid reference system

The Ordnance Survey National Grid reference system is a system of geographic grid references used in Great Britain, different from using latitude and longitude....

 NY 606 660).

Although not now visible, excavation showed that it measures 18.3m east to west by 23.2m north to south. It is built with narrow gauge defensive walls, which are bonded into the Narrow Wall curtain

Curtain wall (fortification)

A curtain wall is a defensive wall between two bastions of a castle or fortress.In earlier designs of castle the curtain walls were often built to a considerable height and were fronted by a ditch or moat to make assault difficult....

 of Hadrian's Wall on either side. It has Type III gateways. It lies 1391m west of Milecastle 49

Milecastle 49

Milecastle 49 , one of the milecastles on Hadrian's Wall, is situated immediately west of the gorge of the River Irthing , where the Wall was carried over the river by the bridge at Willowford....

 and 1501m east of Milecastle 51

Milecastle 51

Milecastle 51 , one of the milecastles on Hadrian's Wall, is situated to the west of Birdoswald fort , at the point where the Stone Wall rejoins the line of the Turf Wall....

.

The stone milecastle replaced its predecessor, Milecastle 50TW (High House) on the Turf Wall, some 200m to the south (OS grid reference

British national grid reference system

The Ordnance Survey National Grid reference system is a system of geographic grid references used in Great Britain, different from using latitude and longitude....

 NY 607 658). This had turf

Sod

Sod or turf is grass and the part of the soil beneath it held together by the roots, or a piece of thin material.The term sod may be used to mean turf grown and cut specifically for the establishment of lawns...

 defensive walls, a timber north tower, and a fragment of a timber construction inscription was recovered.

Milecastle 50 was excavated in 1911 and Milecastle 50TW by F.G. Simpson and I.A. Richmond in 1934.