About the history of the Dome of the Ascension
The Dome of the Ascension, located on the Mount of Olives, is a church that was originally Byzantine and, after being destroyed, was built by the Crusaders in an octagonal shape, with eight pillars with carved capitals and arches between them. In the center of the church was a stone slab with the footprints of Jesus as he ascended into heaven.
With Saladin's conquest of the city, the church became a mosque. Proof of this can be found in the sword's existence in the church's southern wall facing Mecca. The open roof was covered with a dome, the arches closed, the rock with the footprints moved towards the alcove, and a wall was built around it.