I've worked it out though. I don't have a fear of heights. It's a fear of falling and totally mashing my bones up on impact that scares the bejesus out of me.

The last sentence just had me in fits of giggles!!!
why is the stone so black where everyone kisses it?
I'd guess moulds and bacteria have done that over time.
That's actually cleaned regularly which is why the stone there is black, where the rest is grey and speckled.