The Ottoman Empire is often credited with major architectural achievements, particularly during the period known as the "classical age" from the 15th to the 17th centuries. The empire produced iconic structures such as the Hagia Sophia, which it transformed into a mosque, and the Blue Mosque in Istanbul, known for its stunning domes and intricate tile work. Architect Mimar Sinan, considered one of the greatest architects in history, designed many of these monumental buildings, combining Islamic architectural elements with local styles. These structures not only serve religious purposes but also represent the empire's cultural and artistic zenith, influencing architecture across Europe and beyond.