[cheebacheeba]

I think underground and deep ocean is where it's at, more likely than undiscovered/unexplored regions of the land - I mean sure they'd have some stuff we hadn't seen before, unusual centipedes, spiders, insects, animals etc but I don't think anything all that out of the ordinary, more like subspecies or "relatives" to things we've already encountered, perhaps some things thought to be extinct.
Though I say, if you're looking at BIG, and WEIRD, I think you've got to go deeper - places where complete absence of light, higher heat and pressure will either make things appear stranger through adapting to these environments, perhaps "stronger" through dealing with higher pressures, and the deeper, I'd say the larger - say ultra-deep sea, where only something large and incredibly well constructed could really exist without being torn apart.
Funny, if you think about those things rising, it would be interesting to observe just how powerful, manouverable and nigh invulnerable they'd become when so much pressure is off.
I'm sure some would die in the attempt, or get the wicked bends though...but who's to say that's something they'd actually experience - they've gotta have SOME way of dealing with pressure.

So yeah, I'd look more into places we cannot thus far venture.