|the Caves of Chaos|
Are you playing in Mystara? The Keep on the Borderlands easily fits in the north of Karameikos; but can just as easily be placed in North-East Darokin too. I prefer north of Selenica so that it is still near at hand to Karameikos, my favorite realm there.
No matter the world you decide to venture into, the Keep on the Borderlands is something you should seriously consider if you are new to the Fantasy Role-Playing game experience. It doesn't matter which rules system you are using, the material is what matters; not the crunch. Numbers can be replaced easily enough; but when you are pressed for ideas or want to try something that is tried and supported highly by the gaming populace, you won't regret using this material.
I usually just post ideas here, but I would LOVE a discussion with anyone willing to share where and how they have used this awesome material!