The Sultan Ahmed Mosque or Sultan Ahmet Mosque is a historic mosque located in Istanbul, Turkey. A popular tourist site, the Sultan Ahmed Mosque continues to function as a mosque today. The Blue Mosque, as it is popularly known, was constructed between 1609 and 1616 during the rule of Ahmed I. At night the mosque is bathed in blue as lights frame the mosque’s five main domes, six minarets and eight secondary domes.