Here is one of the renders that I created last year using the Terragen program. I entered it in one of the Terragen-related contests.
The Terragen program is available as a free download (please see my other Terragen-related posts) and it is a terrain generating program.
It lets you create, edit and modify terrains. The program also has an option of you adding water to your terrain for sea-like renders. You can also edit the atmosphere and the clouds - as you can see from the picture above.
