Along current Via Matteotti, ancient via Ulpiana, just behind the third circle of walls nearby Porta Romana (Roman Gate), St. Nicolò Church, one of the most ancient churches dated 11th century, stands out. The building was renowned as St. Nicolò de Criptis since it used to stand out on the tunnels of the now-abandoned Roman amphitheatre.
Only part of the facade and its small door with lintel remain today of the original building. On the left side of the ancient Church, the subsequent one dated 14th century, is perfectly placed.
Inside, the unaisled structure was changed between the 12th and the 14th centuries, by adding two minor aisles. Each aisle houses a travertine altar nearby the presbytery.
Outside, the facade displays squared limestone blocks of different sizes. At the bottom centre, the entrance is granted by a majestic pointed arch portal decorated with Solomonic columns, whereas on the top, a beautiful rose window in a sunburst pattern coming from the previous small church, stands out.
Finally, the bell tower is placed at the back of the building.