Re: Ngeh! Seafood soup!
SaGa Frontier had the most ####ing insane areas. The monsters in that game level up with you, too, so levels like the research lab are unbeatable no matter how strong your party is. (Just looked it up and the research lab people mostly use for gaining new skills.)
Blessedly you don't have to go to any of these places in the main quests (not the ones I've completed, at least) or, for the most part, side quests. They're more insanely-hard-dungeon-to-go-in-just-for-loot dungeons.