You look in vain for any trace of the sanctuary of the most celebrated of the Sibyls. Her tomb is pointed out as a vague ruin a short distance from the Necropolis, among the tombs which line the Via Domitiana; and Justin Martyr and Pausanias both describe a round cinerary urn found in this spot which was said to have contained her ashes. The tufa rock of the Acropolis is pierced with numerous dark caverns and labyrinthine passages, the work of prehistoric inhabitants, which have only been partially explored on account of the difficulty and danger, and any one of which might have been the abode of the prophetess. A larger excavation in the side of the hill facing the sea, with a flight of steps leading up from it into another smaller recess, and numerous lateral openings and subterranean passages, supposed to penetrate into the very heart of the mountain, and even to communicate with Lake Fusaro, is pointed out by the local guides as the Sibyl's Cave, which, as Virgil tells us, had a hundred entrances and issues, from whence as many resounding voices echoed forth the oracles of the inspired priestess. But we are confused in our efforts at identification; for another cavern bore this name in former ages, which was destroyed by the explosion of the combustible materials with which Narses filled it in undermining the citadel. This, we have reason to believe, was the cave which Justin Martyr visited more than seventeen hundred years ago, and of which he has left behind a most interesting account. "We saw," he says, "when we were in Cumae, a place where a sanctuary is hollowed in the rock--a thing really wonderful and worthy of all admiration. Here the Sibyl delivered her oracles, we were told by those who had received them from their ancestors, and who kept them even as their patrimony. Also, in the middle of the sanctuary, they showed us three receptacles cut in the same rock, and in which, they being filled with water, she bathed, as they said, and when she resumed her garments, she retired into the inner part of the sanctuary, likewise cut in the same rock, and there being seated on a high place in the centre, she prophesied." But after all you do not care to fasten your attention upon any particular spot, for you feel that the whole place is overshadowed by the presence of this mysterious being; and rock, and hill, and bush are invested with an air of solemn majesty, and with the memory of an ancient sanctity.