Tips on helping animals navigate rocks?

[The Former]

I want to make a rock edifice my animals can walk up, but no matter how gradual the slope seems, my tiger is unable to navigate it. Anyone happen to know why?

[TwinTea]

Under the same option(bottom left) where you see temperature and energy maps, you also have an option to check the area the animal can reach/navigate. Check if there's a point that blocks it for them, It took my lions quite a few years before they wanted to go on the rockslope I made for them and I eventually put up a enrichment toy on the top and then they did start going on it.

Hope this helps!