Hagia Sophia: Istanbul's Architectural Marvel Through the Ages Hagia Sophia stands as one of the world's most significant architectural wonders. The Hagia Sophia has served as a church, mosque, and now museum for over 1,500 years. Its massive dome and stunning mosaics showcase Byzantine brilliance. This UNESCO site remains Istanbul's crown jewel. #HagiaSophia #Istanbul #ByzantineArchitecture #UNESCO #History