lifestyle 16 Liked! 0 Disliked 0 Some of the oldest still-used structures in the world (23 Photos) by: Hendy In: Architecture, History, Lifestyle Feb 5, 2017 16 Liked! 0 Disliked 0 1 source Santa Sophia, Istanbul, Turkey. Completed in 537 A.D. Like this post? 16 Liked! 0 Disliked 0