Parco Archeologico Pausylipon e Grotta di Seiano, Naples

This is an extremely interesting archaeological-tourist route that starts at the Grotta di Seiano at the end of the Coroglio descent. The route follows a tunnel through roughly 770 meters of the tufo Posillipo hill, so joining the area of Bagnoli and Campi Flegrei to Gaiola valley. The tunnel was created about 2000 years ago and reinforced during the Bourbon era. It is lit by openings at the side that let in shafts of daylight and which overlook a superb view. You come out in the area of Villa di Vedio Pollone. The visit lasts about an hour and can only be arranged by telephone.