Geohashing is the pursuit of a purely random point somewhere within a hundred kilometres or so. It's so random it can't be determined ahead of time, and you must get there by midnight, or your whole adventure was a waste of time.
On this particular adventure I cycled from Melbourne, Australia, up through the hills of Warrandyte, Kangaroo Ground, Smith's Gully, into Kinglake National Park, which was obliterated by bushfire in 2009. The roads get steadily worse as I approach my destination, eventually abandoning my bike to fight my way through dense vegetation in pursuit of the prize: a completely nondescript point in the middle of nowhere.
The journey is documented here: http://wiki.xkcd.com/geohashing/2011-10-16_-37_145