The team of archaeologists used gradiometry, a geophysical surveying technique, to look under the soil without the need for excavation.
Gradiometry measures small changes in the earth’s magnetic field to detect archaeological features otherwise invisible from the ground surface. This technique was able to identify the stone base of the fortlet, which remains buried underground. On top of this base, turf would have been laid to build a rampart about two metres high.
It is believed the fortlet would have been part of several such structures along the Antonine Wall which would have been occupied by 10 to 12 Roman soldiers. Historians think they were probably stationed at a larger fort nearby, likely to be Duntocher, and manned the outpost for a week at a time before being replaced by another detachment.
The fortlet would have been made up of two small wooden buildings to house the soldiers and will have been used for the 20 years (142 CE – 162 CE) that the Antonine Wall was defended as the northernmost frontier of the Roman Empire.
“It is great to see how our knowledge of history is growing as new methods give us fresh insights in the past,” said Riona McMorrow, Deputy Head of World Heritage at Historic Environment Scotland (HES).