From the Ra Contact: The Earth sphere is of a honey-comb nature. There were third-density incarnate entities living in the honey-combed areas at one time which are now abandoned cities. Further, there are some inner plane entities of the Earth, some of which live in these areas and at times materialize on the Earth’s surface, and some of which prefer to do some materialization into third-density in these areas. There are also bases in these areas of those from elsewhere, both positive and negative.

Reference

60.21-25