The Church of San Martino in Proceno is known by the town’s inhabitants as the ‘friars’ church’, because in the Middle Ages it was part of a convent complex located on the right side of the building. Originally, the convent was inhabited by Benedictine monks; in 1258, it passed to the Friars Minor Conventual, who remained there until the suppression of religious orders by Napoleon Bonaparte, when the monastery was demolished.

The church, of Gothic origin, is believed to have been built around 1200. The east-facing façade is simple and almost devoid of decoration: in the centre is a travertine portal surmounted by a recessed rose window made of the same material. On the right side of the façade, a section of masonry is still visible with the opening of a door that once connected the church to the convent. The bell gable is supported by a wall that rises about ten metres below the level of the church, then emerges above the structure for a few metres.

Inside, remains of frescoes are still visible on the walls. The presbytery is covered by a ribbed vault supported by four tuff ribs and ends with a large pointed window that illuminates the sacred space. The modestly sized churchyard has a small modern-style altar in the centre. The building was restored after the Second World War, preserving its sober and ancient character.