Most people live in buildings, work in buildings and sleep in buildings. These are often surrounded by other buildings. In many cases, this being surrounded by buildings repeats itself for long distances, until the buildings stop. Once the buildings stop, we’ve reached the bit that is next to all of the buildings. This bit is often not very nice, being the first stop for all of the detritus produced by building the buildings, as well as filled by roads leading to other buildings. After this we come to the bit of nature that most people get to when they walk away from the buildings. This has many hallmarks of nature: birds, trees, grass, rocks etc. It also has many hallmarks of built areas: litter, other people, more buildings. Beyond this final frontier is the nature that people mean when they talk about nature: great expanses, mountain tops, running water, otters and the like. This area is hardest to reach, as there are no buildings here and so very little transport. Often by the time we get here it is almost time to get back to the buildings. As our great concrete crust inches forward, this journey gets a little longer.