On the Gulf. the Atchafalaya Basin.
In New England, Franconian Notch. Is that San Cristobal or El Morro? I always confuse the two. I know I've been to that one twice and the other once. Either would make a great map for the Thief games. :)

Great Smoky Mountains National Park in Tennessee.

Victoria Falls in Zimbabwe. We went on a family trip to Southern Africa way back when I was 11. Just beautiful. No structures and hotels right up to the falls or anything. There's a buffer zone that consists of rainforest you hike through to get there.

http://www.yukiba.com/upl/server/uploads/1281780482-victoria-falls-Zimbabwe-Africa-Victoria-Falls.jpg

here /sarc

Now, as for the OP's question : this place, or [url= http://commons.wikimedia.org/wiki/File:La_vieille_%26_la_plate_%282%29.jpg] this one[/url]. For the second place, the picture doesn't actually say how the place ( Raz de Sein , Brittany, France ) appears wild , seen from the ground. It's even worse from the sea as a bank of rocks extends in the sea for some 15 nautic miles

Santa Fe, NM USA

http://www.rosewoodhotels.com/en/innoftheanasazi/i/SITE_110729_13583652_AE1OB/content/CMS_08012011_114936460_WY5GE/166876F9-188B-3B72-2E95DA2832C0C918.JPG

http://santafe.org/images/Links/4/11484-Abiquiu_pedernal.jpg

Abiquiu is utterly gorgeous but then so much of the state is - that and the whole four corners region. ;-)

El Morro in Old San Juan if you don't, and mabye it would be a setting in Assassin's Creed 4?