More Dungeons in Fiction

So back here, I asked the question, "Does anyone know of any megadungeons in modern fantasy literature?"  I received a few answers (thanks for those, guys) and that gave me some food for thought.

I have a follow-up question, although it is only slightly different from the original, so the same answers might apply.  Does anyone know of any works of fiction that include a "Campaign Dungeon"?  In case you aren't familiar, the term basically means a dungeon that is the main (perhaps only) adventuring locale for an entire campaign of play.

You may be wondering--or perhaps you aren't--why I'm asking questions about dungeons in fiction.  The short reason is because I am actually in the process of writing a story (goal length 60-75k words) that is basically just that--a big old dungeon with a small group of adventurers going into it looking for riches.  My reason for asking is to help me determine if the idea is as unique (in fiction) as I think it is, or is it trite and old.  I have to admit that I haven't read any fantasy is a LONG time and may not know about something that is out there.

So, if you know of something, please speak up.  Thanks.