How Hadrian’s Wall worked
A wall, a ditch, a guarded gate every Roman mile, two turrets in between, forts, and a great earthwork to the south.
Jump to: Size | The plan | Numbering | What you can see
How big?
The Wall is 73 miles long, which is 80 Roman miles. English Heritage: Hadrian’s Wall FAQs UNESCO gives its length as 118 km. UNESCO World Heritage Centre: Frontiers of the Roman Empire (list 430)
It runs from Wallsend in Newcastle upon Tyne in the east to Bowness-on-Solway in Cumbria in the west. English Heritage: Hadrian’s Wall FAQs Roman fortifications carried on for about 25 miles down the Solway coast as part of the wider frontier, but not as part of the Wall. English Heritage: Hadrian’s Wall FAQs
At its tallest the Wall stood about 15 feet (4.6 metres) high. English Heritage: Hadrian’s Wall FAQs It was planned to be 10 Roman feet (3 m) wide but was finished at 8 Roman feet (2.4 m) or less. English Heritage: Hadrian’s Wall FAQs
As first planned, most of the Wall was stone, but the western 30-mile section was turf. English Heritage: History of Hadrian’s Wall The turf sector was 20 Roman feet (6 m) wide. English Heritage: History of Hadrian’s Wall
West of the River Irthing the Wall was at first built of turf; there the milecastles were turf and timber, while the turrets were stone. English Heritage: History of Birdoswald Roman Fort
The plan
The first plan was a wall fronted by a wide, deep ditch, with a guarded gate (milecastle) every mile and two turrets in between. English Heritage: Description of Hadrian’s Wall That gave an observation point every third of a mile. English Heritage: Local Learning, Hadrian’s Wall (teaching resources)
The ditch was dug in front of the Wall except where there were natural crags. English Heritage: Local Learning, Hadrian’s Wall (teaching resources) The Vallum earthwork was built to the south of the Wall, and the Wall was fronted by a wide, deep ditch. English Heritage: History of Hadrian’s Wall
The Vallum was a central ditch between two mounds, 120 Roman feet (about 35 m) wide. English Heritage: History of Hadrian’s Wall Camp followers seem not to have been allowed to settle between the Wall and the Vallum in the early years. English Heritage: History of Hadrian’s Wall
Alongside the Wall there were an earthwork (the Vallum), a ditch, two major roads and many forts, milecastles and turrets. English Heritage: Hadrian’s Wall, History and Stories
A milecastle probably held about eight soldiers in a single barrack block, though some had two buildings and could hold more. English Heritage: Hadrian’s Wall FAQs Turrets were lookout points for small groups of soldiers from the milecastles. English Heritage: Hadrian’s Wall FAQs
Forts on the line
Before the work was finished, 14 new forts were added, together with an earthwork to the south called the Vallum. English Heritage: Description of Hadrian’s Wall The forts were set at a basic spacing of 7⅓ miles, astride the Wall wherever possible. English Heritage: History of Hadrian’s Wall
Early new forts like Chesters straddled the Wall, half to the north and half to the south; a turret was demolished to make room. English Heritage: History of Chesters Roman Fort At Birdoswald the Wall and turret 49a were partly demolished to make room for the fort, which was built astride the Wall. English Heritage: History of Birdoswald Roman Fort
Turret 36b, built with the Wall before the fort, now lies inside Housesteads’ fort walls. English Heritage: History of Housesteads Roman Fort
At Chesters, a large road bridge was built in about AD 160 to carry the Military Way over the North Tyne. English Heritage: Description of Hadrian’s Wall
English Heritage’s pages give different fort counts. More on when sources disagree.
How the numbering works
Archaeologists number the milecastles and turrets from east to west: milecastle 0 is at Wallsend and milecastle 80 at Bowness-on-Solway. English Heritage: Hadrian’s Wall FAQs English Heritage counts 16 forts, 80 milecastles and 156 turrets. English Heritage: Hadrian’s Wall FAQs
What you can still see
Part or all of nine milecastles and one Cumbrian coast milefortlet can still be seen, and sixteen turrets. English Heritage: Description of Hadrian’s Wall The Wall itself survives mainly in the central sector, from Black Carts turret (29a) to Banks East turret (52a). English Heritage: Description of Hadrian’s Wall
- English Heritage lists the forts you can still see, west to east: Maryport, Birdoswald, Carvoran, Great Chesters, Vindolanda, Housesteads, Carrawburgh, Chesters, Newcastle, Wallsend and South Shields (Maryport and Carrawburgh as earthworks only). English Heritage: Description of Hadrian’s Wall
- Milecastles you can see: Harrows Scar (49), Poltross Burn (48), Cawfields (42), Castle Nick (39), Housesteads (37), Sewingshields (35), Shield-on-the-Wall (33), Tower Tye (29) and Westgate Road (4), plus milefortlet 20 (Swarthy Hill) on the Cumbrian coast. English Heritage: Description of Hadrian’s Wall
- Turrets you can see: Banks East (52a), Piper Sike and Leahill (51a, 51b), Birdoswald West (49b), Willowford East and West (48a, 48b), Walltown (45a), Mucklebank (44b), Caw Gap (41a), Housesteads (36b), Sewingshields Crag (35a), Grindon West (34a), Coesike (33b), Black Carts (29a), Brunton (26b) and Denton (7b). English Heritage: Description of Hadrian’s Wall
Most of the Wall is privately owned, by several hundred owners; English Heritage and the National Trust look after well-known sections. English Heritage: Hadrian’s Wall FAQs · checked 29 Oct 2026 English Heritage cares for twenty free-to-enter sites along the Wall. English Heritage: Hadrian’s Wall FAQs · checked 29 Oct 2026
Even official sources don’t always give the same figure for Hadrian’s Wall: how many forts it had, which end was built of turf, or how long the walk takes. Each fact on this site links to who said it, and things that can change, like opening seasons, show the date we checked them. See when sources disagree for every difference side by side.
Next: the forts →