Mercurius
Legend
I don't mean entire world, but a relatively self-contained region that's purpose is to be the starter region for a new campaign. Ideally it would involve numerous adventuring opportunities that wouldn't run out after a few levels, have countless locations to explore, interacting factions, at least a settlement or two, etc. You know, the type of region that you spend the first 5-10 levels in, and then either shift to the Underdark (or equivalent), the larger world, the planes, etc. Nentir Vale is a good example, or the Dale Lands in FR.
What is your favorite and why? Feel free to post maps and links, if it is not well-known product or if you have a wiki of your own.
What is your favorite and why? Feel free to post maps and links, if it is not well-known product or if you have a wiki of your own.