Excavations conducted in the area on which stood the castle of Pietrarubbia are part of a wider project aimed at population analysis of the area of Montefeltro between the feudal period and the beginning of seigneurial power. The excavations which began in 2001 were preceded in 1999-2000 by survey and stratigraphical analysis of the standing features. Earlier excavations uncovered a large two storey residential structure, the lower storey comprising a single room with a central pier irregularly built with split stones. The walls of the building were constructed with sandstones of small, medium and large size, rough hewn or split and arranged in very irregular courses in which a large number of stone wedges were used. The threshold of the wide entrance was formed by a single stone block. Subsequently, walls were built linking the central pilaster to the south and north walls. Perhaps the door providing access from the west was blocked at the same time. As a consequence entry to the building had to be via a wooden stair leading to the upper storey. The removal of the last layers, during the latest excavation campaign, revealed a rudimentary system of channels cut into the bedrock – almost certainly pre-dating the building – which carried water into a small cistern. Numerous fragments of bowls in Renaissance majolica, plain buff coarse ware and finer plain ware, some of which were glazed, a few fragments of slipped graffito ware and Renaissance majolica were found. Also recovered was a high percentage of metal objects (points, nails, a hinge). (Cristiano Cerioni)