Chaotic Caves (which has a keep on the borderlands kinda of feel), and although I quite like the module, I was thinking where exactly is this world? In the module all you get is a map of the area close to the town where the adventure is set. There's a bunch of keyed encounters, (which is quite handy). I've also added a few more including the "Old hermit" from the keep, so its a bit of a mash up. There is also the "Caves" which have a keep on the borderlands feel as well, however there missing the evil priests, and its mostly just monsters. This got me thinking!
I had read somewhere that someone running the keep on the borderlands, used the priests as basically "these evil priest's that are gathering a hoard of monsters to overtake the keep"... Which I love! however that also got me thinking of the Zhentarim. And while reading running the dales I read thru the chapter on "Teshendale" and I put a few things together,
I need some history & a world where the chaotic caves are set - Teshendale
I need a name for these evil priests - Aha! the Zhentarim!
and I've been wanting to run the dales again, so its all working out.
Here's some info on Teshendale (the way I figure, I can explain the town in this desolate dale, as a new town that has just grown up.) That and throughout the Chaotic Caves, there is a variety of encounters with old dungeons, and long forgotten farm lands, it works perfectly.
The other thing I think I'm going to do, is basically do a mashup of the both of the modules. Basically, rather than running the "town" in the Chaotic Caves, I"ll be running the Keep from the keep on the borderlands. But I'll use the map and encounters from the Chaotic Caves. Also I'm stealing the "old fort" from the Morgan'sfort Campagin. so its a total mashup.
Link to the "Dalelands" source book info - http://forgottenrealms.wikia.com/wiki/The_Dalelands_(sourcebook)