From the publisher:
Situated in a high butte near the bend of a river canyon, Havenmine, named for the predicted security of its lofty location, is anything but safe. A few years ago, when chasing a vein of garnets and other precious gemstones, a house of diligent small folk and a tribe of ambitious kobolds met in a most awkward of situations. After many battles, both the gnomes and kobolds began to fortify their halves of the mine, carving the stone to fit their guerrilla needs, the series of traps and chokepoints known as the Havenmine Gauntlet.
The Havenmine Gauntlet is a systemless 9-page ebook detailing a drop-in location for your fantasy game. It includes a general overview of the location, and area-by-area descriptions of the gauntlet, its challenges and traps.