Here are a couple of tweaks I made to your build to show my suggestion based on what you were asking. The first image is my recreation of one of the corridors, where I tried to copy the build but in a stripped-down fashion
The second is what I saw others suggesting (there were too many to credit here but if you did consider yourself credited) where I replaced some of the oak with stripped logs, beehives, and chiseled bookshelves.
The third I went ahead and replaced the whole floor palette and changed it to stone. This one is my personal favorite because it clearly separates the floor from the walls. It also adds some contrast and continuity with the stone in the ceiling.
Let me know what you think overall and if I helped at all.
by Keonmagic22