Y Gaer, Aberyscir, Brecon
The earliest fort was built about AD 75 with defensive banks of clay which rested upon a cobbled surface. A wooden palisade would have protected the defenders. The buildings inside, one of which may have been stabling, were also constructed in wood. At this time the troops at Y Gaer included Vettonian cavalry from Spain. The fort was rebuilt in stone during the second half of 2nd century AD by the men of Legion II Augusta.