Beyazit Square

This was built in 393 during the reign of Theodosius I as the largest square in Istanbul.It situated is in Eminonu district. There was a gigantic triumphal arch in the center decorated by bronze bull heads, hence the name "Forum Tauri" (Square of Bulls).Also it is called Freedom Square.

A few marble blocks and column fragments have been found from the triumphal arch, which was crowned with the statue of the emperor, but nothing remains from the monumental fountain in the northern part of the square. Water to this, the largest fountain in Istanbul, was supplied by means of the Aqueduct of Valens,which brings water from Belgrad Forests,in Sariyer. To the north, the campus of the University of Istanbul now occupies the ground on which Mehmet the Conqueror built his first palace. The monumental gate of the university and the fire lookout tower in the garden are from the 19th century.There is Old Book Bazaar(Sahaflar Carsisi)at the square,which is one of the most attractive parts of Istanbul. The present-day name of the square derives from the Beyazit Mosque, which was built in the 15th century.The mosque, neighboring the always crowded and lively Covered Bazaar, used to have a complex of surrounding buildings, but only the medrese, the baths and some of the shops remain today.

Source: http://english.istanbul.gov.tr