>>721132498
Catalhayouk was a town founded some time around 7500 BC. It had no doors at ground level, everything was accessed via the roof level, they'd have had to lower a ladder to let someone up from the ground level outside the town. It probably to repel raiders, although I'm guessing it might have also served to keep rats and other small critters out since they aren't climbing ladders.
Here is a reconstruction of what the archaeologists at the site think it would have looked like around 7300 BC.