A watching brief undertaken on a construction site in the southern zone of _Teanum_ revealed the presence of a Roman _domus_ occupied between the 1st century B.C. and the 4th century A.D. Three main phases were identified for this architectural complex which stood on artificial terraces which exploited the natural slope of the terrain. The imposing parallel terrace walls in _opus incertum_ and _quasi reticulatum_ belonged to the first building phase. These were identified in the northern sector of the investigated area, on the western edge of which was a room which may be interpreted as a stairwell linking the upper and lower levels of the _domus_. Only the western part of the southern sector was occupied by structures, the eastern side being occupied by a courtyard with a central pool, surrounded by a peristyle of tile built columns. The spaces between the columns were blocked at a later date. In a third phase the floor level of the southern sector was raised and the original pool was replaced by a _nyphaeum_ in _opus reticulatum_. This was enlarged by two subsequent alterations and took on the actual rectangular apsidal form with niches at the ends of the base. The _nymphaeum_, faced on the exterior with painted plaster, had two apses that were richly decorated with a mosaic in polychrome glass paste _tesserae_ and spiral glass canes forming geometric patterns imitating a cane fence. Worthy of note was the presence on the back wall of the pool forming the _lacus_, of three pottery jars set into the wall in a symmetrical pattern. Another three were positioned in the opposite wall but had been obliterated in the latest phase of the alterations. The lack of holes in the jars and their position suggests they were for holding aquatic plants or constituted a refuge for fish.