The grid-work Piri Re'is used is based on isosohedron (20-sided) and dodecahedron (12-sided) geometry. In addition to the cube, all of these geometries have the star-tetrahedron at their root. Points on this grid coincide with volcanoes, mountains, geomagnetic anomalies (such as the 'Bermuda Triangle'), neolithic stone circles, ley lines, and other prominent features. The art of dowsing can be used to locate these features, as well as other energy phenomenon.