The Roman Map of Britain Nemetotalio Nanstallon, Cornwall
Nemetotacio var. Nemetotatio (R&C 4) NEXT
Nanstallon and Lanivet Lannived 1268, Lannyvet 1283 share a spring-fed stream un-named on Ordnance Survey maps. Contrary to conventional wisdom 'church-site at the sacred grove', I take the second element of Lanivet to be the name of the stream, Nimet. See ERN 304 on rivers named Nymet. The Roman fort at Nanstallon sx0367 is positioned on high ground above and just west of the stream's junction with the river Camel. I believe that its name is also derived from the stream name. Its situation would suggest that the common emendation of -tacio/tatio to -statio can confidently be replaced by -talio W tal 'brow, edge, end' (cf. Zerdotalia).
EHNMR-649841 NANSTALLON FORT; LANIVET SX0367