Building my Main base I got a few problems which led to the following ideas:
a triangle rotating wall to close smaller gaps next to stairways.
a wall with half the height
a suspension bridge from one to the next tower or over gaps
wooden crenellations to have a more middle ages flair (maybe also a draw bridge)
an elevator to higher floors or objects in the game
you should also be able to sit in chairs (maybe with a short benefit comming from it)