Snake's Demise.

Baelrick looks at the totems, at first, they don't really seem to have any meaning, but then Baelrick remembers an old encounter he had a long time ago, and he can finally assign a meaning to those totems. They are definitely of goblin make. The sort of totems they put at the edge of their territory to mark it, and also as a warning to any who would trespass on their turf. Those are a bit different than the ones Baelrick saw in his younger days, but that could simply be a regional thing, or perhaps each tribe have their own style...

@Tyr: If any reptile has evacuated waste here, it doesn't seem to be recent enough for it to have left any evidence.

@Daglin: Daglin at least knows this wall is not of dwarven make. Though it seems to be a few centuries old, no dwarven architecture would be half crumbled like that after such a short length of time. Given the wall's state, it's difficult to determine it's exact dimension, but it does run between one steep outcropping of stones to another, making an outward curve as it goes.

Well, first thing first, before you make your way to the caves, both Baelrick's mule and Thorbojorn will refuse to climb over the rubbles to get closer (both would probably risk breaking a leg going over it, and there's plenty of brush and grass outside for them to eat without risking a broken leg). If you want them to follow you, it will require an Influence or a Nature Lore check.
Concerning Baelrick's mule, there is also the problem of the cart which can't navigate the rubble, so if you want to go through with it, you'll have to push/lift it, which will be an Athletics check at -50%, but on which assistance is possible (see p.17).
As for Bean and Freyja, they'll follow you no problem.
Once you'll pass the wall, you'll find yourself in a canyon-like formation and you'll eventually reach the mouths of the caves, which will look like that (with the crumbling wall being several dozen meters off-map to the west).