There is another free library to do that, among other things, by Google. It's not well known, but it was used all over the place internally (at least by the geo

There is another free library to do that, among other things, by Google. It's not well known, but it was used all over the place internally (at least by the geo team). https://code.google.com/p/s2-geometry-library/ https://code.google.com/p/s2-geometry-library/ The key difference with geohash is that it uses a Hilbert curve instead of a z-curve and it projects the world in a cube instead of using directly cartesian coordinates.