Nanstallon in 1965 by Aileen Fox and Professor W. L. D. 'Bill' Ravenhill. Until recently (2007) it was the second Roman fort in Cornwall but following a geophysical survey another Roman fort has been found away near Restormel Castle. Constructed c. AD 55–60, Nanstallon fort is situated in mid Cornwall near the Fowey-Camel trade and communication route. Nanstallon was probably a forward operating base and was strategically well-placed for a Roman presence to be felt. However, the Roman Legion at Exeter was withdrawn c. AD 75 and with no Roman town west of Isca Dumnoniorum Cornwall settled down to four centuries
Isca Augusta River Usk. The suffix "Augusta" appears in the Ravenna Cosmography and was an honorific title taken from the legion stationed there. The place is commonly referred to as "Isca Silurum" to differentiate it from Isca Dumnoniorum and because it lay in the territory of the Silures tribe. However, there is no evidence that this form was used in Roman times. The later name, "Caerleon", is derived from the Welsh for "fortress of the legion". Isca was founded in AD 74 or 75 during the final campaigns by Governor Sextus Julius Frontinus against the fierce native tribes of western Britain, notably