but I can’t see an analogous one for Christianity
I'm not one to bring down any religion but I would gladly bring down a point for their argument. The second rock is not Christian at all. The second one is under the Dome of the Rock in Jerusalem. The only Christian rock that I could think of would be Peter. Jerusalem had been a fighting point for Dark Age Christians but that was just fear of the different. I think we have out grown that argument; most of us at least.