UNEDITED:
http://www.imperial-library.info/content/oblivion-battle-sancre-tor,
its citadel on high cliffs overlooking the lower city, nestled in a high mountain basin with steep, unscalable cliffs in their rear.
but
http://www.uesp.net/maps/obmap/obmap.shtml?centeron=Sancre+Tor
The citadel is in the city; there are no other ruins around.
Why would you make up lore FOR A GAME (this book only appears in Oblivion) and then go against it??
EDIT: Oh, and I can think of some excuses, but I want to know what you guys think