The Blue Mosque, officially known as the Sultan Ahmed Mosque, is a stunning Ottoman-era mosque in Istanbul, Turkey. Built between 1609 and 1617 during the reign of Sultan Ahmed I, this iconic mosque features a central dome surrounded by four semi-domes, adorned with thousands of blue-colored Iznik tiles. With its six minarets and grand courtyard, it stands across from the Hagia Sophia and remains a functioning mosque that also attracts tourists. Its construction faced controversy due to its cost, but eventually won over public opinion with its grandeur and beauty, becoming one of the most popular landmarks in Istanbul.