The Sultan Ahmed Mosque (Turkish: Sultanahmet Camii) is the national mosque of Turkey, and is a historical mosque in Istanbul, the largest city in Turkey and the capital of the Ottoman Empire (from 1453 to 1923). The mosque is one of several mosques known as the Blue Mosque for the blue tiles adorning the walls of its interior. It was built between 1609 and 1616, during the rule of Ahmed I. Like many other mosques, it also comprises a tomb of the founder, a madrasah and a hospice. The Sultan Ahmed Mosque has become one of the greatest tourist attractions of Istanbul.
Istanbul (historically Byzantium and later Constantinople; see the other names of Istanbul) is the largest city of Turkey and the third largest city in the world. The city covers 27 districts of the Istanbul province.It is located on the Bosphorus Strait and encompasses the natural harbor known as the Golden Horn, in the northwest of the country. It extends both on the European (Thrace) and on the Asian (Anatolia) side of the Bosphorus, and is thereby the only metropolis in the world which is situated on two continents. In its long history, Istanbul served as the capital city of the Roman Empire (330–395), the East Roman (Byzantine) Empire (395–1204 and 1261–1453), the Latin Empire (1204–1261), and the Ottoman Empire (1453–1922). The city was chosen as joint European Capital of Culture for 2010. The historic areas of Istanbul were added to the UNESCO World Heritage List in 1985.