In the heart of Isernia’s historic center, in Piazza Andrea
d’Isernia, stands the Cathedral of Saint Peter the Apostle, the main church of the Diocese of Isernia-Venafro. This important religious building is not only the spiritual hub of the city, but also an extraordinary archaeological site, as it was built over an Italic pagan temple dating back to the 3rd century BCE, originally dedicated to the Capitoline triad: Jupiter, Juno, and Minerva.
Significant remnants of the ancient temple still remain, including the travertine podium, now integrated into the cathedral’s foundations. Some of the original materials were reused for the Christian structure, making it harder to reconstruct the exact look of the temple, which was likely abandoned and used as a quarry for building materials over time.
The current appearance of the cathedral is the result of
numerous renovations, often due to the frequent earthquakes that have struck the region. Attached to the church is the bell tower, known as the Arch of Saint Peter, named after the large pointed arch at its base through which Corso Marcelli passes. Restored in 1456, the tower features four Roman statues and houses a civic clock and two bells that mark the hours.
A remarkable example of historical and architectural layering, telling over two millennia of sacred and civic life in the city.