A node is a point where the energy is focused on earth.
Nodes are always marked as special, with some architectural feature or landmark singling them out.
Nodes in wilderness areas are often marked with stone circles or single megaliths.
Nodes are not natural but artificial, constructed by magical techniques that were known in generations past and are now largely forgotten.
They must, however, be constructed in places where stellar energy is naturally concentrated, meaning that they cannot be built according to convenience.
This rarely happens in more than one location within a 50 mile radius, so the
Nodes are quite widely spaced.