Terragen Classic is very old software. You can tell. But despite having more clunky menus than Windows 3.1 and a render preview so small you'll get permanent eye damage from the intense squinting required to make sense of it, it's still capable of producing striking environment renders to this day.
The four showcased here were the products of my first experiments with it. The first two were more freeform while the latter pair had a stronger sense of direction.