At the fast travel location near the farm on the map, there is a glitched area that you can walk into to enter walls with weird textures. I don't think this is a known bug.
In my video I show in more depth where it is, how to get there, and what it looks like inside.
PLEASE nobody take credit from me for finding this though. I normally don't discover things in games, because I don't normally wander. This was my discovery and mine alone.
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Pretty cool, the strange textures are just from them not being properly textured and wasn't expecting anyone to actually see them