The ancient Hippodrome, the scene of chariot races and the center of Byzantine civic life, stood in the open space in front of the Blue Mosque, an area now called Sultanahmet. Of the monuments which once decorated
 it only three remain: the Obelisk of Theodosius, the bronze Serpentine Column and the Column of Constantine. Remains from the curved end section of the Hippodrome's wall can be seen on the south side of these three monuments. Today the square forms the center of Istanbul's historical, cultural and touristic activities. You should take particular note of the surrounding wooden houses, particularly the 18th century ones on Sogukcesme Street. Delighttully restored, they have new life as small hotels; one houses a fascinating library of books on Istanbul.

The Ahmet Ill Fountain, built in 1729, stands at the entrance to Topkapi Palace. Deep overhanging eaves shade the water spouts where the parched could stop for a cup of refresning water. This highly ornate, free-standing fountain is a superb example of the late Ottoman style.

Mahmut II built the Beyazit Tower (85 meters high) in 1828 as a fire tower. Today it stands within the grounds of Istanbul University

The Bozdogan-Valens Aqueduct, built in 368 A.D., supplied the Byzantine and later the Ottoman palaces with water. Today part of the remaining 900 meters of double-tiered arches straddle the major highway that runs through the old part of town.