The Benedictine settlement has been documented since the year 829 and the Church of San Pietro was built in the area which was part of the fortified city of the late archaic period. The building was destroyed in the landslide of 1956 the most serious catastrophe which struck the town of Vasto. It is one of the oldest and most attractive areas of the town, rich in public and private buildings of inestimable historical and architectonic which stretched out in a half-moon shape along the promenade of Via Adriatica, which was swallowed completely by the abyss.
Nonetheless what remains today of the original Church of San Pietro is the façade and beautiful late 13th Century portal, an authentic documentation of medieval art. The lunette of the portal depicts the Madonna holding a baby in her arms, with his hand raised in blessing. In a rectangular cornice below is a portrayal of the Crucifixion, where Jesus wears a royal crown, not of thorns, a very rare example of illustrations of this type.
The magnificent fragments give an idea of how richly the entire façade must have been decorated. At the base of the walls, at the sides of the portal, are some remains of walls datable to the 1st Century A.D., which some studies attribute to a temple dedicated to Ceres.