"DA1 Adventures in Blackmoor" TSR 1986

[Havard]

I agree that this module is somewhere between an adventure and a gazetteer. You can run the adventure and still have a huge amount of extra setting information that allows you to run a sanbox or create a number of other linear adventures in the very same location.
Some descriptions are at times even eccessive

It reminds me in many ways of B2 Keep on the Borderlands or X1 Isle of Dread. Although unlike those two modules, the DA series is of course written for much higher level characters so they can be a match for characters from Dave Arneson's original campaign late in their careers.

-Havard