Eminönü is a district of Istanbul in Turkey. This is the heart of the walled city of Constantine, the focus of a history of incredible richness. Eminönü covers the point on which the Byzantine capital was built. The Galata Bridge crosses the Golden Horn into Eminönü and the mouth of the Bosphorus opens into the Marmara Sea. And up on the hill stands Topkapi Palace, Sultanahmet (The Blue Mosque) and Aya Sofia. Thus Eminönü is the main tourist destination in Istanbul.