I owe the group some info on the world they live in. The name of the continent/world is Pallaster and the region in which this begins is known as the Dragon’s Eye. The adventure will begin just north of the city of Harrowport – a small city built upon the ruins of a much larger and older city whose history is unknown to you. The sea is directly to the east, to the north and south are mountain ranges that meet in the west on the other side of the valley. So Dragon’s Eye is fairly secluded (and probably resembles an eye if I drew a damn map for you, in case you didn’t guess).
Magic is mostly the stuff of legend and fairy tales though it undoubtedly exists. It’s just that people don’t see it much and what they do see is low level tricks and illusions (see Prestidigitation in the PHB). Life mostly consists of farming, crafting and other low-tech pursuits – standard medieval fare.
Stories and legends abound. Just as the history of the great city predating Harowport is unknown to you, there are stories of other great ruins in the greater world. Also, you all have heard some version of the following:
Long ago there were great civilizations until calamity struck. A great war/natural disaster/act of God or the gods destroyed the civilization and killed the Great People leaving what you have now. In some versions, this fall from grace was earned, in others it was a tragic and avoidable outcome.
In the Dragon’s Eye, where mountains and the raucous sea surround you, people tend to lean toward the natural disaster version though, as the saying goes, you get all types.