Roman ruins of Pisões, Roman archaeological site in Santiago Maior, Portugal.

Roman ruins of Pisões are the remains of a large residential complex with numerous rooms decorated with black and white tile patterns. The site includes bathing facilities and storage areas that show this was a prosperous settlement.

The complex was occupied over several centuries by a wealthy family and served as a major food production center. The buildings show changes across different periods that reflect how the settlement evolved.

A small altar found at the villa was dedicated to the goddess Hygieia, and the name Gaius Atilius Cordo carved on an altar stone identifies one of the owners. Two Visigothic capitals and black ceramics show the site was still used after the Roman period.

The site is located inland and requires a car or organized tour to visit. The path crosses farmland and some remains are fully excavated while others remain partially buried under earthen mounds.

The dam north of the villa was a gravity structure 58 m long and 4.3 m high, built of small diorite blocks set in opus incertum and faced with larger stones. Abel Viana described it in 1947, noting two openings at its base, one arched in brick and probably a bottom discharge. It closed a basin of 18.6 km².