In the late Middle Ages, six gates were built in the walls of the village of Pettorano. Porta San Marco is one of the five which still remain. It was originally called the gate "of the stains" because it forms part of the road of the same name which leads to the church of San Rocco. Probably nearby was the site of a church dedicated to the saint who then gave his name to the door and to the area of around it. The round stone arch of the gate is surmounted by a statue of St. Anthony of Padua, which is placed between two pinnacles. On the right of the gate you can see a stone sundial set into the wall of an 18th century building. Underneath is also set a Roman tombstone dating from the second century. A.D. The insciption probably refers to a Lucius Vibius, a family name that we find in many local documents.