The Roman fort at Nanstallon stands on the south western edge of Bodmin Moor, overlooking the River Camel near Boscarne, about two and a half miles west of Bodmin. It is one of the most important Roman military sites in Cornwall and is often described as the most southerly and westerly known Roman station in the British Isles. Built during the reign of Nero, it was probably occupied from around AD 65 to AD 79. Today, the fort survives mainly as earthworks, but excavation has shown that it was once a carefully planned military installation in a strategically important position. The site was chosen for its control of movement through the landscape. Nanstallon overlooked one of the lowest fords across the River Camel, giving it command of a key crossing point. It also lay within a wider corridor between the Camel and the River Fowey, making it useful for monitoring movement inland across mid Cornwall. Although Cornwall is often thought of as being beyond the main zone of Roman military control, Nanstallon shows that the Roman army had a direct presence here during the first century AD. Excavations between 1966 and 1969 revealed the fort’s layout and construction. The defences were formed from clay ramparts thrown up between turf revetments, enclosing an area just over two acres in size. The fort measured about 290 feet east to west and 330 feet north to south. Its gateways were built from timber and included six posted structures and towers. Particularly notable were the rare double portal gates, comparable with examples from only a small number of other Roman military sites in Britain. Inside the fort, archaeologists found evidence for barrack blocks, the principia, or headquarters building, the praetorium, which housed the commanding officer, and an ablutions block near the south east gateway. The barracks were relatively simple rectangular buildings, without the projecting officers’ quarters found at some larger forts, although larger rooms were present at the ends. The principia was unusual because of its broad design, with long halls on either side of its courtyard, a recessed entrance, and a portico. These details suggest that, although Nanstallon was small, it was not a temporary or careless construction. The fort was probably too small to hold a full auxiliary unit, so it may have housed a detachment with a specific local role. One possibility is that the soldiers were involved in supervising or protecting lead and silver extraction in the surrounding area. Finds from the site support this idea, including evidence for metalworking, hearths, trenches, and crucibles beneath one of the barrack rooms. Coins ranging from the late Republic to the reign of Vespasian, along with samian ware pottery dated to around AD 50 to AD 80, help confirm the fort’s short period of occupation. Nanstallon appears to have been abandoned around AD 79 or soon after. The evidence suggests an orderly dismantling rather than destruction in battle. The site also contains traces of earlier activity, including flint tools, showing that this part of the Camel Valley had been used long before the Roman army arrived. Today, Nanstallon remains a rare and valuable example of Roman military presence in Cornwall. Its earthworks and buried remains provide important evidence for how far Roman power reached into Britain’s far south west, and how the army may have controlled routes, resources, and movement through the Cornish landscape.