Best old-school dungeon to get stuck/live in

[Nagol]

[MENTION=85158]Dandu[/MENTION]
It depends. In crook stories its almost always "the necklace", or in adventure stories "the artefact", or in spy stories "the papers". In McDonalds its probably the "secret sauce".

It's the burgers! That's what Hamburgler is after! The burgers I tell you!

 

[Lord Ipplepop]

The Temple of Elemental Evil would be my suggestion. It is crawling with monsters; however, if he was captured and forced into servitude, he would be able to survive long enough for the party to rescue him... plus there are all of the elemental "dungeons" that would be large enough for him to hide.