The branch that goes from the Porta di S. Lorenzo to the other reservoir, under the Trophies of Marius, is carried on a fine arcade of the first century; this has been brought out far more clearly than it had been for many centuries. The remains of the reservoir at this very high level are also made visible. Signor Ernest de Mauro, the surveyor who took the levels, considers this branch so high, that the only water that could reach it was that of the Claudia and Anio Novus united, which we know from Frontinus was carried into all the fourteen Regiones of Rome, but it was considered by Fabretti to have belonged to the Aqua Julia; the difference of level between the two aqueducts is only ten feet. At this high point the water was divided, and carried in different directions; one branch, of which part of the _specus_ is visible, went to the other great reservoir called the Sette Sale, which supplied the Thermæ of Titus and Trajan on the Esquiline, and the surplus water passed on to the Colosseum and to the fountain called the Meta Sudans. From the other great division of the aqueducts, at the corner of the Sessorian gardens, near the Porta Maggiore, the well-known arches of Nero go along the bank to the Lateran, and from thence along the Cœlian Hill to the great central reservoir of Nero, over the Arch of Dolabella. At that point it has been already shewn that several of the aqueducts met, and were divided into three branches, one straight on to the Palatine, on a double arcade across the valley from the Cœlian, of which there are considerable remains of the lower tier of arches, and one arch of the upper tier, which forms a sort of back gate to the palaces of the Cæsars. A second branch passed over the Porta Capena to the Aventine, at different levels; the earliest and lowest, the Aqua Appia, is the one that can now be the most distinctly traced. After passing over the short _agger_ of Servius Tullius it goes underground under the cliff, at the north end of the Pseudo-Aventine, and at the further end under the hill on which S. Sabba now stands; a series of stone-quarries have been made by cutting away one side of the _specus_, leaving the wells to give air to the quarry.