The ancient town of Aquinum was situated in the middle Liri valley, at the foot of the Mount Cairo range (1.669 m). It stood on a vast plain, with three ancient lakes to the east, now drained and reclaimed (Vallone di Aquino), where the left affluent of the river Liri runs, known as Le Forme di Aquino. The modern town of Aquino is situated west of Roman Aquinum, beyond the vallone.

Among the research activities undertaken by the Laboratory of Ancient Topography and Photogrammetry at the University of the Salent, Lecce, is the “Ager Aquinas project”. This territorial research began in 1998 with field work which has produced a digital aerial photogrammetrical reconstruction at a scale of 1:2000 of the urban and suburban area of the ancient town, aimed at the drawing up of an archaeological map and reconstruction of the town plan. The topographical investigations, backed up by a careful interpretation of the aerial photographs, geophysical survey and, from 2005, by an aerial survey of the territory undertaken at low height, led to the reconstruction of the urban plan of ancient Aquinum and, specifically, the identification of a residential quarter in the centre of the ancient town, with single buildings aligned along the roads.

Taking these factors into consideration, the excavation programme for 2009 at Aquinum foresaw the opening of two trial trenches within this central area of the town, identified thanks to the aerial and geophysical images. archaeological interest in this zone is also stimulated by the toponym “San Pietro Vetere”, although to date no elements of particular use for the definition of the urban plan had been found there. The first trial trench brought to light an opus reticulatum wall on an east-west alignment, with evidence of robbing which began in the late antique period and continued into the medieval period. In the area of the trench south of the wall stone elements from the kerb or sidewalk belonging to a road on the same alignment were uncovered. In the second trail trench, situated to the north-east of the first, walls belonging to various rooms of a bath complex, perhaps public, were uncovered. At least three different rooms were identified, a first which the presence of suspensurae in the floor and tubuli in the walls suggest can be interpreted as caldarium or laconicum, a second as a small access area with mosaic which led into the complex and a third open room interpreted as an apodyterium. In the latter room there was a mosaic inscription (1st century A.D.) inside a tabula ansata mentioning two individuals, probably the builders or restorers of one of the rooms in the bath building.