I think my other worst experience wasn't an awful place but it was a night in the States a few years ago where we had a stunning air bnb cabin in the mountains. Unfortunately we got pissed in the local town, my brother lost his jacket which had both our car key and the cabin key. Had to instead check into a very budget motel where we were four to a room and get our hire car towed the next morning and get a replacement at a fairly substantial cost and miss our one night in the amazing airbnb