Here is a fantasy adventure start for a new Campaign (or for adventures entering a new land with some modification).
It is the last hot days of fall, and as with every season you find your selves on carts loaded with bricks. Your five day journey from your homes is almost at an end, for just over the next hill you can see the the top of the Wall.
From your many previous trips you know that the next week will be hard, back breaking labor. The Lord Tyrant has ordered, as did her father, and his Mother before and so on, all must repair The Wall: make it strong, make it stout, keep the luminous clawing darkness out. All must repair The Wall so that the world doesn't end...
For the GM:
The wall is actually a vault sounding a gate and a ruin. For the last thousand years or more people have always come and built the wall up: a little thicker; a little taller; trying to keep the aberrant creatures that dwell on the other side at bey.
Or maybe it is something else, something of your own devious design?