Krosul's Kofaadsa is a crowd-sourced old-school fantasy adventure setting. Scattered about a free map from FreeFantasyMaps.org are award-winning entries from the One-Page Dungeon Contest and some free modules that got a thumbs-up from Ten Foot Pole. These are some of the best adventures available on the internet, free or otherwise. There are still plenty of blanks to fill in, but most of these adventures are just a couple days away from each other, so you don't have to fill a lot in if you don't want to. No historical background is provided, as it is expected that this will emerge through play.