In the fork where a cross-road called the Via Ardeatina branches off from the Appian Way, is a little homely church with the strange name of "Domine quo Vadis." It is associated with one of the most beautiful legends of the early Christian Church touchingly told by St. Ambrose. The Apostle Peter, fleeing from the persecution under Nero that arose after the burning of Rome, came to this spot; and there he saw a vision of the Saviour bearing His cross with His face steadfastly set to go to the city.