Upon the side towards the Sea of Marmora the wall proceeded from the main gate of the city to the point occupied by the temple of Aphrodite, and to the shore facing Chrysopolis.[25] The temple of the Goddess of Beauty was one of the oldest sanctuaries in Byzantium,[26] and did not entirely disappear until the reign of Theodosius the Great, by whom it was converted into a carriage-house for the Prætorian Prefect.[27] It was, consequently, a landmark that would long be remembered. Malalas[28] places it within the ancient Acropolis of the city. Other authorities likewise put it there, adding that it stood higher up the hill of the Acropolis than the neighbouring temple of Poseidon,[29] where it overlooked one of the theatres built against the Marmora side of the citadel,[30] and faced Chrysopolis.[31] From these indications it is clear that the temple lay to the north-east of the site of St. Sophia, and therefore not far from the site of St. Irene on the Seraglio plateau. Accordingly, the wall of Severus, upon leaving the western gate of the city, did not descend to the shore of the Sea of Marmora, but after proceeding in that direction for some distance turned south-eastwards, keeping well up the south-western slopes of the First Hill, until the Seraglio plateau was reached.[32] As these slopes were for the most part very steep, the city, when viewed from the Sea of Marmora, presented the appearance of a great Acropolis upon a hill. Where precisely the wall reached the Sea of Marmora opposite Chrysopolis is not stated, but it could not have been far from the point now occupied by the Seraglio Lighthouse, for the break in the steep declivity of the First Hill above that point offered the easiest line of descent from the temple of Aphrodite to the shore. Thus it appears that the circuit of the walls erected by Severus followed, substantially, the course of the fortifications which he had overthrown. It is a corroboration of this conclusion to find that the ground outside the wall constructed by Severus—the valley of the Grand Bazaar—answers to the description of the ground outside the wall which he destroyed; a smooth tract, sloping gently to the water: “Primus post mœnia campus erat peninsulæ cervicis sensim descendentis ad litus, et ne urbs esset insula prohibentis.”[33] To this account of the successive circuits of Byzantium until the time of Constantine, may be added a rapid survey of the internal arrangements and public buildings of the city after its restoration by Severus.[34] A large portion of the Hippodrome, so famous in the history of Constantinople, was erected by Severus, who left the edifice unfinished owing to his departure for the West. Between the northern end of the Hippodrome and the subsequent site of St. Sophia was the Tetrastoon, a public square surrounded by porticoes, having the Thermæ of Zeuxippus upon its southern side.