During my time in Canada, I learned about a stack of rocks called an inukshuk (plural: inuksuit).
Now, I'm not an expert by any means, but these babies are supposedly placed along trails to guide travelers to food, water or shelter. They acted as a reference point for hunting grounds, etc.
The first time I noticed them was while driving through Ontario. Every once in a while, I'd see a stack of rocks on the side of the road. It turns out that some people still carry on the tradition by building them by the highways.
Granted, it's not that hard to get lost on Highway 1 in Canada, and you can bet that a paved road will lead somewhere. Still, I thought it was an interesting tradition.