A number of the Elder Scrolls games have similar areas and enemies (for example that one quest in Morrowind where you have to transport into a room
totally separate from any other area that exists basically in a void and fight a unique enemy), and for an example of story, that hidden Prothean orb in the first Mass Effect game that gives Shepard a flashback of Protheans observing and messing with caveman - era humans is haunting and
unlike anything else in the game (and sadly pretty much never gets explained in the
rest of the franchise).