The abbey of San Pietro ad Oratorium is a Benedictine abbey near Capestrano. It is located in the point where the valley narrows down, near two important communication channels: Claudia Nova and the Tirino River. The monastic settlement was founded during the 8th century by Desiderio and it was later rebuilt following a Romanic style.
The interior is divided into three naves, at the end of which we find an apsis. There are also rounded arcs laid upon stone columns, and inside the presbytery there is a ciborium from the 13th century. The apsidal basin is covered in frescos painted during the 12th century.
The exterior presents a façade with regular stone blocks that reach the height of the lateral naves. On the external wall, there is a tombstone with the inscription “Rotas opera tenet arepo sator”. The only entrance is enriched by vegetable decorations.