The remains of a long-lost Roman fortlet that once stood next to the Antonine Wall have been rediscovered by archaeologists. The find was made in an ‘unassuming’ field near Clydebank’s Carleith Primary School in West Dunbartonshire, Historic Environment Scotland (HES) announced last month.
The fortlet would have been one of several along the Antonine Wall, which was constructed across central Scotland by the Romans in AD 142. This frontier was the northernmost border of the Roman Empire for 20 years, until it was abandoned in favour of the more southerly Hadrian’s Wall in 162.
Made up of two small wooden buildings, the fortlet would have housed around 10 to 12 soldiers, who were stationed at a larger post nearby, likely to have been at Duntocher. The fortlet would have been manned for a week at a time, before each detachment was replaced by another.
The Carleith fortlet was referred to by antiquarian Robert Sibbald in 1707, who noted that he had seen the remains of such a building in the vicinity of the nearby farm of the same name. Previous excavations to find it, which took place in the 1970s and 1980s, were unsuccessful.
But now new technology – such as gradiometry – has finally allowed HES’s archaeological survey team to pin down the fortlet’s location.
Gradiometry measures small changes in the earth’s magnetic field, allowing archaeologists to look under the soil without having to excavate.
The technique was able to identify the stone base of the fortlet, on top of which turf would have been laid to build a rampart about 2m high.
The discovery, announced on 18 April this year to mark World Heritage Day, is only the tenth known fortlet to have been found along the wall. A total of 41 fortlets are believed once to have lined the frontier, which is now a UNESCO World Heritage Site.
Commenting on the discovery, Riona McMorrow of HES said that it was ‘great how our knowledge of history is growing as new methods give us fresh insights into the past.’
‘Archaeology is often partly detective work, and the discovery at Carleith is a nice example of how an observation made 300 years ago and new technology can come together to add to our understanding,’ she added.