Istanbul’s Sultan Ahmed Mosque is commonly known as the Blue Mosque because of its blue interior tiles.
Built between 1609 and 1616 during the reign of Sultan Ahmed I, the mosque stands opposite Hagia Sophia in Istanbul’s historic peninsula. Architect Sedefkâr Mehmed Agha designed it as a major imperial Ottoman mosque.
The nickname refers especially to the Iznik tiles used inside, many of which feature blue tones and floral or geometric patterns. The building’s six minarets were unusual when completed and contributed to its commanding cityscape.
The mosque remains an active place of worship, so visitors must follow entry rules outside prayer times. Its popular nickname is informal: the official name is Sultan Ahmed Mosque, after the ruler who commissioned it.