A deep subterranean development. The TAR is a Geofront. Geofronts are also known to be the Headquarters of major corporations. Bertrave features more than one. They are often virtually self-sufficient so some of them in the world have dubious sovereignty. They always have some form of self-sufficiency. Almost all of them run off their own nuclear power plants. Sometimes Geofronts are also the titles of power plants themselves.