Nuruosmaniye Mosque Complex The Nuruosmaniye Mosque is an Ottoman-era mosque from the 18th century located in the Çemberlitaş neighborhood of Istanbul, Turkey. In 2016, it was included on Turkey’s Tentative List of World Heritage Sites. The mosque is especially known for its distinctive dome, ranking as the fourth largest in Istanbul, following the Hagia Sophia, Süleymaniye Mosque, and Fatih Mosque. Serving as part of a larger religious complex known as a Külliye, the Nuruosmaniye Mosque functions as a hub for cultural, religious, and educational activities within the community. It holds the distinction of being Istanbul’s first imperial mosque built in the Ottoman Baroque architectural style. The mosque's muqarnas and its gently curved courtyard reflect the Baroque style. It is situated on Istanbul's second hill, the former site of Fatma Hatun's mosque, which was lost to a fire. The Nuruosmaniye Mosque is also close to the historic Forum of Constantine, where the Column of Constantine still stands today. The mosque is surrounded by the bustling Grand Bazaar. Known as the "Light of Osman" in honor of Sultan Osman III, the mosque was initially built during the rule of Sultan Mahmoud I (1748–1754) and was completed by his brother and successor, Sultan Osman III (1755–1808), in 1755. The mosque’s name comes from Osman III and also highlights its 174 windows that brighten the main prayer hall. The prayer space is covered by a single dome measuring 25 meters (82 feet) in diameter and rising to a height of 43.50 meters (142.7 feet). This dome is supported by iron reinforcements extending from the floor through the walls up to the dome’s ceiling. The mosque is constructed using cut stone and marble. Its overall design emphasizes the transformation of straight lines into smooth curves. The complex includes two minarets, each featuring two balconies. The mosque’s courtyard is uniquely shaped like a horseshoe, a rare feature among Ottoman mosques. The Nuruosmaniye Complex stands as an outstanding representation of the Ottoman Empire's political, social, cultural, and artistic accomplishments in the late 18th century. The introduction of a new architectural style within the complex is considered the peak of the era’s aesthetic and design evolution, reflecting the broader socio-cultural transformations of the time. The Nuruosmaniye Complex embodies a blend of artistic and technical exchanges between the Ottoman Empire and Western Europe, showcasing a cultural fusion and the local reinterpretation of European architectural influences. The complex combines innovative ideas with traditional elements. Baroque motifs were incorporated not only in the complex’s public fountains but also in prominent buildings and mosques constructed throughout the 18th and 19th centuries of the Ottoman era. In 2016, the Nuruosmaniye Mosque Complex was added to the UNESCO Tentative List, recognizing its historical and cultural importance.