In 1979 six young speleologist discovered an incredible story that happened centuries earlier under the ruins of a Dominican convent. The first building that they found in front of their eyes was a 12th-13th century rupestrian church, completely frescoed with picture of Christ merciful and bleeding, the four symbols of the Evangelists, the Coronation of Mary and, particurarly important, numerous portraits of Saint Michael the Archangel, to whom the church had been dedicated, then reconsecrated in 2000. After reopening a walled up door, they found themselves in a long corridor that led into a large hall, once occupied by the "Room of Torments", thus called in the documents found in the Vatican Archives, used by the Inquisition for the interrogations and in a small cell that has preserved the enigmatic graffiti of a prisoner locked up in 1759: Giuseppe Andrea Lombardini.
Today, this can all be seen thanks to guided tours by the volunteers who discovered it and who have retrieved the story of these places of suffering in archives all over the world. The visit ends up in the magnificent church of Santa Maria Maggiore, now of San Domenico, transformed into conference rooms, which until the 13th century was the cathedral of Narni. In this place, it is possible to admire the recent archaelogical discoveries, including a splendid 6th century Byzantine mosaic.