The gyrus is a large circular structure on the east side of the fort. This feature is unparalleled in Britain.The ring is 34.06m in diameter with a funnelled entrance and double gate, probably indicating that the structure was used for livestock of some sort. Archaeological excavations uncovered finds associated with cavalry. This strongly suggests that the gyrus was once a cavalry training arena where the soldiers stationed in the base trained horses for combat. The surface of the arena was kept smooth and level and was covered in sand. The Greek historian Xenophon referred to such a structure as a ‘gyrus’, but there is no equivalent Latin word.
Though the gyrus was not part of the initial fort design, it was obviously an important part of the fort. When the structure was added, two barrack blocks were shortened and one was moved to accommodate it. Once built the arena remained a constant feature while the rest of the camp continued to be altered and developed. The gyrus was the last part of the fort to be dismantled in AD78. It is thought that the gyrus was used as a stockade for soldiers and supplies when the fort was being taken apart.
Cavalry Training Ring
This large circular feature is unique in the Roman Empire. It is 34.06 metres (107 feet) in diameter and has a double gated, funnelled entrance. The archaeological evidence suggest this was a cavalry training ring.
Following the Boudiccan Revolt, the Lunt may have been a centre for breaking and training horses seized from the Iceni – or Celtic horse people. Since horses were in constant demand by the army, they would be welcome spoils of war. A large wooden post in the centre of the Gyrus could be used for weapons practice, learning to cut and stab with the gladius (short Roman sword) or throw and thrust with the pilum (spear).
More archaeological evidence suggests that earlier barrack blocks were demolished or shortened to make room for the building of the Gyrus.
The reconstruction of the Gyrus was completed in 1977. 18 men from 31 Base Squadron working 6 hours a day took 10 days to complete it.
Sleeper beams were first set into the perimeter trench and then uprights were set into these. A fence was constructed all the way around the circular arena with a double gate built at the each end of the entrance.