The new theatre, like the old one, was erected in the enclosure of Dionysus Eleuthereus. This enclosure lay at the foot of the Acropolis, by which it was bounded on the northern side. Its southern boundary may possibly be identical with certain fragments of an old wall, marked x in the plan. Within the enclosure were two temples of Dionysus, of which the foundations have recently been discovered. The oldest, marked _t_, was the nearest to the Acropolis, and is assigned by Dörpfeld to the sixth century. It contained the ancient image of Dionysus Eleuthereus which was carried in the annual procession at the City Dionysia. The more recent temple (_u_) lay a few yards to the south of the old one. In it stood a gold and ivory statue of Dionysus made by Alcamenes towards the end of the fifth century. The temple itself was probably of the same date.[331] Near this temple are the remains of a square foundation (_w_), also of the fifth century, which possibly served as the basis for an altar.[332] The site chosen for the new theatre was almost identical with that of the old one, but lay a few yards further to the north-west. The reasons for this change were apparently twofold. By bringing the auditorium closer to the Acropolis, it was possible to make a more extensive use of the slope of the hill as a support for the tiers of seats. At the same time a larger space was left between the orchestra and the old temple of Dionysus, and so afforded more room for the stage-buildings. In one respect the position of the theatre differed from that usually adopted in later times. The auditorium faced almost directly towards the south. This arrangement was generally avoided by the Greeks, and Vitruvius expressly warns architects against the danger of adopting it, because of the terrible heat caused by the midday sun glaring into the concavity of the theatre.[333] But at Athens there were special reasons on the other side. If the theatre was to be built in the enclosure of Eleuthereus, the only natural position was along the slopes of the Acropolis, and facing towards the south. The rising ground supplied an excellent foundation for the central portion of the auditorium. The choice of any other situation would have involved the erection of costly and elaborate substructures. The Athenians, therefore, from motives of economy, preferred the southern aspect, in spite of its obvious disadvantages. The same course was also adopted in the theatres of Eretria and Syracuse. In proceeding to describe in detail the form and construction of the theatre it will be convenient to take the different portions in succession. A Greek theatre is naturally divided into three parts, the auditorium, the orchestra, and the stage-buildings. In the following description the auditorium will be considered first, the orchestra next. The stage-buildings, as forming the most difficult part of the whole subject, will be reserved for the last. § 4. _The Auditorium._