Fodor's Expert Review Catacomba di San Giovanni
Not far from the Archaeological Park, off Viale Teocrito, the catacombs below the church of San Giovanni are one of the earliest known Christian sites in the city. Inside the crypt of San Marciano is an altar where St. Paul preached on his way through Sicily to Rome. The frescoes in this small chapel are mostly bright and fresh, though some dating from the 4th century AD show their age. To visit the catacombs, you must take a 45-minute guided tour (included with the admission price), which leaves about every half hour and is conducted in Italian and English.