The Hagia Sophia is an astonishing building. Pictures do not adequately convey the scale of it. It should remain a museum. Astounding Christian mosaics lie under iconic Muslim plaster. Until recently, a delicate balance was struck in uncovering mosaics while preserving plaster. It was an attempt to balance the history of the building between it's creators and those who now control it. Turning it back into a mosque will most likely involve covering up those mosaics again. This is a loss to world history.