Earth node

An earth node was a geological anomaly beneath the surface of Faerûn. They usually existed only at points were the invisible streams of arcane magic that permeated Faerûn intersected. Those creatures in tune with arcane magic could sometimes sense the presence of a node. The power field of nodes varied from approximately 30 feet (9 meters) to 1/2 mile (0.8 km.)

Description
The physical form of earth nodes varied but could take the form of a giant geode or a strangely regularly shaped cavern.

Uses
Some arcane casters were able to tap into the power of a node and occasionally nodes could be used as teleportation devices.