The remains of ancient Naples are still visible below the modern city, giving life to a downtown full of contradictions. The guided tour also includes the visit the monumental complex of Pietrasanta, with a portion of the old acqueduct, built in a tufa cave and then used as shelter during the WWII. Last stop of the guided tour is Piazza San Gaetano, the ancient Neapolitan forum (main square), to visit the ruins of the Roman market under the Church of San Lorenzo Maggiore.