There are several springs or sources for this aqueduct, and also several ponds to collect the rain-water, made in the clay, the water from all of which was collected into a central reservoir cut in the rock, with a large well over it. There are also seventeen wells visible in two lines, eight in one and nine in the other, converging and meeting in the central reservoir. The soil is clay upon stone. The _specus_ is here a large tunnel cut in the rock, and the wells descend into it. They may be distinguished from above by the bramble-bushes which grow over and cover each of the openings, and do not grow on the other part of the field; each well is also protected by a wooden rail, to hinder cattle from falling into it. The water still runs through in some parts. Near to this reservoir is a tomb of very early character, similar to what are usually called Etruscan[13] tombs, cut out of the rock. As the length of its course was rather more than eleven miles, while the distance by the Via Prænestina direct was only between seven and eight, it is clear that it did not follow that road. It was carried to the south towards the Via Labicana by a winding course, according to the levels of the ground. The Aqua Virgo, whose source is in the same Lucullan fields as the Appia, is carried to the north by another winding course of a greater length, to supply the northern parts of the city. The course of _the old Via Prænestina_[14] has undergone but little change, and the 7th milestone is soon measured. A little beyond it, and 780 paces off on the left of the road (i.e. on the northern side), we are brought to a point[15] where the sources of the Aqua Appia are still to be seen in caves formed by ancient stone quarries, near a tenement called _La Rustica_. One cave is of a triple form, with three springs, and the soil above the stone is much mixed with clay. These three springs meet at the mouth of the cave in one stream, which runs in the old _specus_ cut in the rock, but open at the top, and having the appearance of a mere country ditch, half hid by the grass and weeds in the winter, and in the summer months entirely concealed by them. This _specus_ runs across a low meadow for about a quarter of a mile. It crosses the line of the Aqua Virgo, the respirators of which cross this meadow in an opposite direction; the sources of the Virgo are about a mile further from Rome, on the same road. It then enters the rock again in a tunnel, and at this point is the first _castellum_ or reservoir, with a large circular well cut out of the rock, which forms the vault over it. There are the grooves for sluices at each end of the reservoir, and an opening has been made into the tunnel a little beyond this reservoir. The course of the aqueduct is then in a tunnel entirely underground, in the direction of a series of ancient caves, through which, or by which, it must pass, but being underground it cannot be seen. These caves are evidently an ancient