Occasionally you stumble upon something strange. Not outright threatening, but bearing an elusive quality that sparks an interest and resonates with a part of your mind you didn't know existed. Trinkets nestled in the rubble of derelict buildings. A mysterious CD in the back alley of your workplace. A skull in the woods.
These are artifacts of a nonexistent culture. The significance they bear is comprised solely of what they inherently have to offer and what you have to bestow upon them.