Fodor's Expert Review Pausilypon Archaeological Park
Located at the top of Posillipo's hill, this small yet magical complex has a 1st-century villa and two amphitheaters; access is though the Grotta di Seiano, a 2,500-foot tunnel cut though the tufa rock over two millenia ago. Free guided tours (in Italian, book ahead) are given at 9:30 and 10:30, weekdays, with more detailed tours given at weekends. Evening concerts are often held here in the summer.