The religious complex of Neuville-sur-Sarthe is divided into three zones.

To the west a vast rectangular enclosure (60 x 40 m) surrounds a fanum, Gallo-Roman temple, in the tradition of Celtic temples, later monumentalised. The construction of this type of edifice, generally on a square plan, is characterised by a central room dedicated to the divinities the cella, surrounded by a peripheral gallery where the faithful walked in procession.
This main fanum is a vast temple of 15 x15 m. The few fragments of architecture discovered lead one to think that it was of Corinthian style with painted walls. It is completed by five small buildings or ´†side chapels†ª on a square or octagonal plan. A large enclosure, or temenos, made of masonry walls, delimits this sacred space.
Abundant archaeological remains, dating from the first century AD have been found there.

The south zone is incomplete and presents a large fanum of circular plan, 12 metres in diameter. At its side is an auxiliary temple, smaller and on a square plan.
One of the distinctive features of this fanum, apart from its circular plan, is to have an entrance facing north, contrary to most temples whose entrances face east. Numerous pole holes nearby allow one to envisage the presence of a pergola about fifty metres long exalting the entrance to the temple. The archaeological goods, of a later date than the precedent (2nd and 3rd centuries AD), are also less abundant.
 
In the north zone, a vast building on a E plan (8 x 8 m.) is situated in the exact continuation of the entrance to the main fanum of the west zone. Apart from a function of welcome and of guidance of pilgrims, it was also probably used as accommodation for the guardians or a sales point for objects to be later offered to the gods.