Its a British thing. Just another excuse to drink beer . When I was in Europe last year I was invited to go Hashing. A group of people get together at a pub or bar (I think that The Hash House was the origional) and one of them lays out a route for everyone to try to find and follow. The path eventually leads back to the pub/bar/restaurant where everyone continues to socialize. The path is laid out by arrows that are made with flower, chalk, arranged stones or whatever works. The arrows are sometimes hidden and if you pass it or miss it, you have to go back to find it.
Some of the Hashers really have a competitive spirit and run (or bike) the route by themselves, but many people just do it to socialize and walk in groups (a great singles get together, sometimes). That is where "on on" comes from in my title because the ones not really competing help the people behind them out by yelling "on on" for a straight arrow, "on right" for an arrow pointing right. etc.
When you mentioned caching being a good way to discover an area, I thought of this because they Hash in cities, villages, out in the country, and even on and near beaches and it is a great way to learn the surroundings and see the sights.
I had asked those guys over there if it was common in other parts of the world and, as it turned out, not only is it well known the world over, but there are a couple of Hash House Herriers' chapters in the Washington D.C. area. Apparently, it started in India by a bunch of British expatriates and since Brits had a former colony in every section of the world, it has spread over the decades to non British participants world wide.