San Pietro, in the historic center, of which only the remains remain (lower part of the facade), following the landslide of 1956, is located in the square of the same name that before the landslide, connected to the road that led to the sea, commonly called « Via delle Lame », diction not so much originated by warlike deeds as by a Lombard loan meaning« swimming pool ».
This church was the most dear to the people of Vasto. Of the ancient facade only the lower part remains, within which the beautiful Romanesque portal is set, slightly later than that of the Cathedral (around 1200), well finished in the grooves carvings; in the lunette you can admire a fine example of Christ Infante, and, below the tiny sculpture, an expressive and delicate bas-relief depicting the Deposition of Jesus having a royal crown and not the usual crown of thorns, a rare example.
The interior of the church, originally, was also Romanesque; later it was badly restored, so that the primitive octagonal columns were covered with stucco cages that diminished its simple and bare beauty. A plaque found there clearly shows how the Romanesque building was built on the remains of a temple previously dedicated to Ceres.