Of the eighteen gates, which once existed on the west side of the city, only seven now remain. The site of the two temples erected by Justinian, as _safeguards_ of the city, may still be ascertained by their vestiges; but these have almost disappeared. The walls, which are well built, are still standing, and consist of stone terraces from fifty to sixty feet high, and occasionally from fifteen to twenty feet thick, covered with freestone of a greyish-white colour; but sometimes of pure white, and seeming fresh from the chisel of the mason. At the feet of the walls are the ancient fosses filled with rubbish and luxuriant loam, in which trees and pellitories have taken root ages ago, and now form an impenetrable glacis. The summit of the wall is almost everywhere crowned with vegetation, which overhangs and forms a sort of coping, surmounted by capital and volute of climbing plants and ivy. These walls are so noble, that La Martine says that, next to the Parthenon and Balbec, they are the noblest existing memorials of ruined empires. "There is nothing either grand or beautiful in the remains of the brazen column, consisting of the bodies of three serpents twisted spirally together. It is about twelve feet in height, and being hollow, the Turks have filled it with broken tiles, stones, and other relics. But in the circumstances of its history, no critique of ancient times can be more interesting. For it once supported the golden tripod at Delphi, which the Greeks, after the battle of Platæa, found in camp of Mardonius[157]." Near the Valide is a COLUMN of PORPHYRY[158], generally supposed to have supported the statue of CONSTANTINE. It is composed of eight pieces, surrounded by as many wreaths or garlands of the same marble. Not long since it gained the name of Colonna Brugiata, or burned pillar, having been very much defaced by the many conflagrations to which this vast city has been subject. Near Mesmer-Kiosch[159] is a view of the summit of the Corinthian pillar of white marble, fifty feet high, in the gardens of the seraglio, with the inscription-- FORTUNÆ REDUCI OB DEVICTOS GOTHOS. This has been erroneously supposed the column of Theodora. Pococke mentions that it was taken from some other part of the town to the seraglio gardens. It is supported by a handsome capital of verd antique. This building[160], the mosque of St. Sophia (formerly of much larger extent), owes its foundation to the emperor Justinian, who lived also to see it finished, A.D. 557. It was dedicated by him to the wisdom of God. This fabric is entirely Gothic.