This guy has done a ton of traveling across central and South America and has pictures for each state that he's traveled.
It takes a bit of digging but it's interesting to see the different vegetation/landscapes/buildings. (Look for the thumbnails link for each state) It's where I've been getting some ideas for in terms of the landscape. I've done a few sketches but not happy with them yet, I'll be posting some stuff within the next day or so though.
Hope this helps layout team!!