Remove natural=* from climbing POI?

I think there might be some confusion. You posted a picture which @milet was able to track down. I looked for an object that had exactly the same tags. I found https://www.openstreetmap.org/node/7737629440 and had that in mind when I replied earlier, and that does have natural=stone on it.

More generally, that whole area has a bunch of “climbing” examples you might be able to draw inspiration from.