Is it real or is it
Terragen? Believe it or not this
image is 100% digitally created. Everything you see was rendered using a program called Terragen (for Windows or Mac). That's 'terra' = Latin for earth or land i.e. terra firma and 'gen' for generator.
The program is free for home users and the only limits applied are the size of the output file is limited to 800x600. Still if you really want to produce poster-sized outputs pay the $80 to register.
The cool thing is that anybody can create these awesome looking landscapes by fiddling around with the various menus that control the number sets used by the program to make the renderings.
That means that if you limit the ground to 200 ft altitude and the valleys to 350 Ft below sea level, plus make the water table level 15 Ft below sea level, the resulting output will show a realtively flat landscape with a lake that surround land gently sloops down too.
Try it some time. The program is small, but of course the tax on your system to generate a rendering is brutal. Forutenately Terragen lets you previews what the output rendering will basically look like infinetly until you actually are happy and want to make a big one. Depending on the detail level of the "world" you are creating (and layers of details are as limiting as a photoshop file with 500 layers) it may take 2 minutes or 45mins. I have made some animated output frames that take 3 minutes a piece and I needed 40 frames a second for 3 minutes (thats 40x60x3=7200 frames) at 3 minutes apiece or 15 days of straight rendering.
I might have to get a big faster machine before I try to render something the likes of Shreck2 again.