How about something along the lines of a world once ruled by magic and mythic creature, etc, etc. The strongest of which being the mighty dragons. They brought piece and justice to the lands and humans worshipped them as god'like creatures. At some point in history a band of humans challanged their status as protectors and became the first dragon slayers. Dragons crawled int othe earth and left man to their fates. Now over a thousand years later the world of industry and technology has grown into a Steampunk style land. All the magic and mythical creatures have been mostly forgotten. Whats left of the lot is hidden away in a forest far from the human cities, maybe across a wasteland. The evil rulers of this new land are the great decedents of the slayers. Now a small group of heroes have to travel, for some reason, into the wastelands in search of the legendary dragons to help take back the land.
just a rough idea?