From the introduction:
The Bightwater Region is so named for its primary city, Bightwater, a port town. The region can be roughly broken into two eras. Many thousands of years ago, the area was a significant portion of the Eburnean Empire. This empire was both technologically and magically advanced, and many vestiges of their reign can still be found in the dark corners of the Bightwater region.
Following the fall of the empire (the ultimate cause of its fall was unknown) the more recent era saw the settlement of Bightwater by halfling merchants, who established a successful trade industry for several decades. Many wealthy halfling families thrived during this time, and their influence can still be felt today in the city. Roughly three human generations ago, barbarian invaders conquered and displaced many of the halflings. This resulted in a variety of different halfling settlements in the region. As the invaders began to settle in the newly-conquered region, certain halflings have returned to the city, its surrounding areas, and the trade industry. There remains a tense, uneasy peace between the city's inhabitants and surrounding settlements as a result of this history.
Beyond Bightwater is a system-neutral hex crawl. The project was a collaborative effort involving many from the RPGGeek community.