https://en.wikipedia.org/wiki/Great_Pyramid_of_Giza#Casing_s...
What does that mean? I don’t think the pyramids have been smooth for a very long time.
Also I am doubtful that sliding down one of the great pyramids would be particularly fun. Aside from the abrasion even a “smooth” pyramid would cause, I’d expect you’d pick enough speed up that the impact would kill you.
To put it another way, citation?
You could certainly walk up it fine.
Citation needed for sure and the authorities must have never encouraged it and I'm not sure why it'd be super fun to slide down but given the popularity of hiking, rock climbing, sledding, skiing, and snowboard it's totally logical people would want to go up and down it it.
That's assuming I still know how to trig, and it's entirely possible I don't.