Blue MosqueBlue Mosque, Istanbul, Turkey.(more)Blue Mosque, 17th-century mosque that is one of the most magnificent structures of the Ottoman Empire, set next to the Byzantine Hippodrome and across from the Hagia Sophia in Istanbul, Turkey. Known for having six minarets (rather than the standard four) and for its many domes and semidomes, the building became known as the Blue Mosque for the color of its interior, but it is in fact properly known as the Sultan Ahmed Mosque—named after Sultan Ahmed I, who ordered its construction.

　　Blue Mosque interiorInterior view of the dome of the Blue Mosque, Istanbul, Turkey.(more)The Blue Mosque was built between 1609 and 1616 in what was then the center of Istanbul. Its position opposite Hagia Sophia suggests that Ahmed I intended the mosque to rival the glory of the former catheral. The mosque’s architect, Sedefkar Mehmed Ağa, is responsible for the perfect proportions of its structure. The carved marble minbar (pulpit) is positioned so that the imam can be heard from anywhere in the mosque. The central dome of the mosque is 77 feet (23.5 m) in diameter and 141 feet (43 m) high, and it is supported by four large pillars and surrounded by eight cascading smaller domes. The interior of the mosque is lined with more than 20,000 handmade ceramic tiles from İznik, which are richly decorated with flowers, trees, and abstract patterns. Above the tiles the walls are painted with various motifs, generally in a blue color. More than 250 stained-glass windows allow daylight to flood in. Ahmed I died shortly after the mosque was completed and is buried in a mausoleum just outside the walls of the mosque.

　　The Blue Mosque holds about 10,000 worshipers, and hundreds of Muslims use it for daily prayers five times a day, with many more attending on Fridays and during Muslim festivals. The mosque is open to tourists when it is not in use for worship. The way in for non-Muslims is by the south entrance, but the west entrance is the most superbly decorated.