Oh! I'm picturing a well (hole in the ground, stone wall defining the opening) surrounded by another wall, a few feet out from the well's wall. (You're right, that is super awkward to describe.) But it sounds like there's just the one stone structure, immediately around the hole in the ground, and no second structure around that one?

I pictured two walls because standing directly on the stone structure that's around the hole in the ground seems risky, especially for addressing a crowd - what if someone jostles you and you fall in? Bad enough if Libris falls in, but if Murra falls down the well then all their plans are moot. I'd think Ellis would object, at least, if she hops up on a wall that has a deep hole directly behind it.