Visit Hagia (St.) Sophia, one of the greatest marvels of architecture, constructed as a basilica in the 6th century by Emperor Justinian. St.Sophia has been the largest cathedral in the world for nearly a thousand years. It is considered the masterpiece of Byzantine architecture. After having been the Patriarchal basilica of Constantinople, it was converted into a mosque in 1453 by Sultan Mehmet II. the Conqueror and in to a museum by Atataürk in 1935. Explore the Blue Mosque, facing Hagia Sophia, famous with its blue Iznik tiles and unique with 6 minarets, built in the name of Sultan Ahmet. The last great imperial mosque of the classical period, its name comes from the 20,000 marvelous blue-toned Iznik tiles decorating the interior walls. Discover the Hippodrome, center of sportive (chariot races, athletics) events and political activities of the old city. Obelisk of Theodosius, Serpentine Column, German Fountain of Wilhelm II are the monuments decorating Hippodrome. You will also see one of the oldest and largest covered markets in the world, The Grand Bazaar.