What kind of areas would you like to see in Act 4?

Act 4 confirmed! WOOO! Obviously GGG is already working hard on Act 4 areas and this thread is not meant to tell them what to do.

What I would like to see:

1. A desert area. Yeah I know, its been done to death by Blizzard, but I just went on a road-trip to Southwest US and it was so beautiful. Anything from the bright red rocks and messas of the grand canyon, to the flat, white, dry land I saw around Mexican border with haunting abandoned Indian villages, plus real sand desert like you see in dune areas of the Oregon Coast. All would make excellent levels.

2. Mountain/snow biome. Again, Blizzard did it but they did everything. Nothing more beautiful than the sight of a mob massacre on pristine white snow.

3. What makes POE unique is the slight steampunk sensibility they mix into the gameworld. Think the robotic enemies in Act II (including boss) and the giant machine you see as you ascend towards Dominus. It gives the game a cool post apocalyptic vibe, like we are running on the ruins of some formerly great civilization we cannot comprehend. I think it would be awesome to have atleast one area where these aspects of the game are emphasized and the player is running around some kind of rusty, rotting steampunk area full of broken machines.

Any other ideas?

Snow please.

Snow

skyrim esque

There will be organs quest in act4, swamps confirmed.

snow then we can have snowman as the new pet! or penguin! or new skill such as snowstorm.

skyrim

More epic indoor areas a la Solaris (without desync-inducing doorways). No more dank caves - game has enough of those already.

I'd like to see the Highgate's mines where virtue gems are extracted.

And a extradimesional area like Diablo 2 Act 2 or Planescape: Torment.

a massive volcano !!!