I don't think the Earthgift Shrine and pals should actually count, but if they do, Earthgift Shrine, because of the DAMN DESERT.
All the other special dungeons were pretty cool though. So many kickass floors 
EDIT: I can't seem to remember the Marsh Cave, anyone tell me what exactly there was to do there?
Get the Crown for the king in the Western keep and then. hahahaha he turns in dark elf king astos
you kick his ass in a battle then you get a crystal ey go to matoya's cave and give it to her.you recieve the jolt tonic
and then go back to elfheim,go to the castle and give it to sleeping beauty,(prince)
(dude i should make walkthroughs)
