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11/02/2025
There were up to 80 milecastles on Hadrian's Wall, a stone frontier structure built by the Romans in northern Britannia in the AD 120s. Milecastles were guarded gateways through the Wall and would have been garrisoned by up to 30 men, although it probably varied depending on the location of the milecastle. These fortlets had internal buildings for the men and horses, as seen here in this brilliant reconstruction drawing of Poltross Burn Milecastle (Milecastle 48) in what is now Cumbria, England. For how it looks today, there are photos in the comment section.
Hadrian's Wall was 80 Roman miles long (73 modern miles), with a milecastle built every Roman mile, approximately. In addition to these small forts, there were up to 160 observation towers (turrets), two spaced at a third of a Roman mile intervals in between each milecastle. However, each milecastle probably also had a tower above its north gate, which would mean there was a tower every one third of a Roman mile along the Wall, approximately—up to 240 towers in total. The Wall also had (arguably) 16 large forts, 13 of which were definitely attached to it.
Hadrian's Wall forts from west to east (all forts are located in northern England). Tick for the forts that are/were attached to the Wall:
1. Maia (Bowness-on-Solway)✅️
2. Concavata (Drumburgh)✅️
3. Aballava (Burgh by Sands)✅️
4. Uxelodunum/Petriana (Stanwix)✅️
5. Camboglanna (Castlesteads) Not attached
6. Banna (Birdoswald)✅️
7. Magna (Carvoran) Not attached
8. Aesica (Great Chesters)✅️
9. Vercovicium (Housesteads)✅️
10. Brocolitia (Carrawburgh)✅️
11. Cilurnum (Chesters)✅️
12. Hunnum (Haltonchesters)✅️
13.Vindobala (Rudchester)✅️
14. Condercum (Benwell)✅️
15. Pons Aelius (Newcastle) Might have been attached
16. Segedunum (Wallsend)✅️
Uxelodunum was the largest of these forts and was garrisoned by the Ala Petriana, an elite cavalry regiment.
This list does not include nearby forts such as Luguvalium or Vindolanda, both of which are just south of Hadrian's Wall.
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📷A reconstruction drawing of the milecastle at Poltross Burn as it may have looked around AD 170. Because the structure was built on a slope, the internal buildings had to be terraced and stepped to form usable rooms with level floors. The ravine of the Poltross Burn is visible at centre right, with Hadrian’s Wall heading east beyond. © Historic England (illustration by Peter Lorimer)