The fifth excavation campaign on the site of Coriglia (Saint Anselm College NH, USA with the municipality of Castel Viscardo and the Archaeological Superintendency of Umbria) took place in May and June. The campaign aimed to investigate particular sectors in order to resolve questions relating to the use of a number of structures which emerged in previous years, and to the site’s general topography.

The 2010 excavation saw the extension of two areas (F and A), continuation of work in C and the opening of a new trench in G with the aim of defining the development of a wall in an unexplored zone.

The extension to the north of area F was of great interest as it exposed the entire perimeter of the tank partially exposed in 2009. This quadrangular structure (3.40 × 6 m) had an opus signinum floor and quarter- round molding at the base of the wall. The uniformity of the material in the tank’s fill (numerous fragments of opus doliare, architectural terracottas, amphorae, as well as marble crustae and millstone fragments) suggest that the tank was intentionally filled in antiquity. The presence of ARS and a coin of Gordian III (243-244 A.D,) date the fill to around the mid 3rd century B.C. The use of archaeometric instruments (XRF – Raman) on the concretions revealed the presence of chemical elements such as calcium, sodium, potassium and sulphur in quantities similar to those in the sulphureous waters of Monterubiaglio.

Trench A, extended to the south by about 4 × 5 m, came into contact with the water-table. Here a 10 m length of wall (yellowish mortar and cobbles) on a north-east/south-west alignment was uncovered. It crossed the excavation area on a diagonal as far as one of the previously identified terracing walls. A via glareata with a road bed made up of small, well-packed cobbles bedded in compact earth may be of late Roman date. On a north-east/south-west alignment (cf. above) it was three metres wide and bordered by larger stones.

In trench C investigations aimed to define the building techniques used for the bath structures. In the inner part of the exedra, excavated in previous campaigns, a water pipe came to light (a lead fistula with hammered edges) which headed towards a quadrangular structure interpreted as a fountain. In the northern strip of the area the stratigraphy indicated the continuation of the structures in that direction (sections of wall, drains).

Trench G, 4 × 4m, documented the continuation of the containing/enclosure wall towards the west. The east-west arm crossed trenches A, B and E where it turned at 90° towards trench C. The find of a coin attributed to Pope Clement VIII (datable to around 1600) provided further information regarding the occupation of Coriglia.