i'm not sure if it has anything to do with the graphics or level design or if i'm just having a hard time with my memory lately, but a lot of the dungeons and building interiors in oblivion are extremely difficult to navigate thanks to everything looking very...samey?
also, the wilderness feels pretty bare.
the game does let you fast travel basically anywhere you want to go even without previously going there so long as it's on your map, so that does help, even if it feels kinda like cheating