These two churches are placed side by side and connected by a series of arches opening into a communal part. They represent one of the most suggestive and interesting organisms of the city.

On the right we can see the oldest, dedicated to S. Oliva, patron saint of Cori since Medieval. According to an inscription found on the façade, it seems that an old Christian structure existed already from the II century, built on the remains of a Roman temple dedicated to Giano.