A 19th century drawing of the view from Camp Hill (location of the temple) south-east towards the River Severn (Bathurst (and King) 1879: pl. II / photo from RSOT)

The site is situated on the edge of the Forest of Dean, on the south-western tip of a spur overlooking the River Severn, about a mile from the estuary shore. It is also close to one of the principal Roman roads into south-east Wales, towards the legionary fortress at Caerleon and the civitas capital of the Silures at Caerwent (Venta Silurum). Caerwent is 19km to the south-west, while the colony at Gloucester (Glevum) was 28km to the east. South of the temple two villa sites have been found in close proximity to one another, which perhaps housed the sponsors of the sanctuary, whose scale makes it one of the largest and most imposing religious complexes known from Roman Britain.

The Roman sanctuary represented but one phase in a long history of occupation on the site. In the Iron Age the spur on which the shrine sits was defended by multiple banks and ditches to the north and a single rampart on its eastern side. At some period prior to the construction of the temple, mining of iron ore took place on the spur, as elsewhere in the Iron Age and Roman period in the Forest of Dean. The temple was probably built in the later third century AD, along with other buildings.