The earliest documentation of the presence of this church, sometimes known as Santa MM, dates from 1128. The building is constructed from irregular masonry and mortar, with an open area at its base, which in its turn is bordered by crumbling dry stone walls. The interior has a terracotta floor and above the altar there is a high-relief sculpture of a small cherub with one arm missing and a vandalised face. The font and the altar have also been damaged. The lower part of the east facade contains a walled-up doorway and a window, while the upper part rises to a bell tower constructed from blocks of tuff. The north side presents a set of steps which lead up to the area where the faithful would gather. An opening in the west side, about half a metre above ground level, served as access to the snow storage area. These spaces often resembled swimming pools and look like almost habitable rooms created below ground. Their barrel vaults are covered by a sloping roof and they differ from normal surface constructions in that they are generally higher from floor to ceiling.