At the moment there are two suspension bridges on the Bosphorus Strait connecting Europe to Asia. The third one is under construction.
At the moment there is a tunnel under the Bosphorus connecting Marmaray rail system between Europe and Asia. The second one, called as Eurasia Tunnel, is under construction and this will be for motor vehicles.
At the moment there are two international airports; one on the Asian side one on the European side. The third one is under construction.
Istanbul has the third oldest subway in the world, built in 1875. It's 573 meters long and located in Tunel neighborhood at Beyoglu district. London subway was built in 1863 and New York subway in 1868.
Grand Bazaar is the biggest old covered bazaar in the world, with over 3.000 shops.
Hagia Sophia was the largest church in the world for about 900 years.
Four bronze horses which are decorating today San Marco Cathedral in Venice, were taken from Istanbul (Constantinople back then) by the Crusaders in the 13th century.
First traffic accident occured in 1912 at Sisli district, when the driver of the Italian Embassy hit a pedestrian and tried to run away from the scene.
Sapphire skyscraper at Levent district is the tallest (261 meters - 856 feet) building between Dubai - Frankfurt on the world map. Second tallest building in Istanbul is Is Kule owned by Is Bank, 181 meters (594 feet) high.
During the Middle Ages in the Ottoman Empire, Istanbul had over 1.400 public toilets in the city meanwhile there weren't any even at the palaces in France and other European cities.