Forest is a nice landscape:
and its two lovely add-ons which I do not own, but look awesome:
Just a note that those are bit heavy resource and have long rendering times, but if you don’t mind that they do make gorgeous renders.
Gosh… okay that Andre makes a ton of nice sets, cave and snow and others too…
Now, if you use Daz studio, and want a landscape tool with more mileage, I HIGHLY recommend infinito…. make your own landscape, and populate it with trees and grass and flowers, even make caves. It’s worth the price to make your own landscapes, set up a scene and make your landscape match your own needs and vision. I absolutely love making my own scene!!!! Less cookie cutter and more wow factor ^^
SOOOOOOOO worth it!!
And If you have LAMH its great for low resource grass and instancing
I haven’t really needed to buy many landscapes since buying infinito,but i couldn’t resist Flipmode’s lovely easy environment sets: http://www.daz3d.com/flipmode They give the illusion of a huge huge space and render much faster. Gorgeous (I only have sands and snow sets but others are in my wishlist!!)
Hope that is helpful