Game environments are not built with a ruler and some tape, they are built with imagination and an understanding of what is needed to make the game environment. If you take the time to learn about what you will need to do before you being the process, it will make for better results in less time with less work.
It has been said that within the mountains (or was it the darklands?) there dwells a fluffy creature of immense cuteness. This creature is so adorable that all who encounter it are filled with joy so great their mortal forms cannot contain it. And they explode. Several magic institutions are desperate to study the creature or better yet capture one to prove the theory of an elemental plane of "D'Awwww".