Vladimir "Vlaad" Kuzmanov has composed an interesting article on the Aesthetics of the Adventure Map.

The purpose of this topic is to share my experience and get some feedback from other authors and players alike.
It is said a picture is worth a thousand words, so I’ve included some examples. The screenshots were taken from my favorite scenarios and campaigns, although I do understand I may have missed some gems. Feel free to list your own favorites.

One will find a number of great posts dealing with gameplay, but few threads deal with the looks of the adventure map. Hardcore players, especially veterans who prefer online multiplayer, might say that you should stick to random maps. This missive will mostly discuss single player and RPG maps, where the settings are as important as the balance or the story.

If you haven't already, you should also check out some of the older articles on Map Making here.