I have usually posted on some Facebook HE sites in order to keep them alive with some decent material. But the following is a Facebook, hollow earth page which I have never seen before. It has 6,700 members! I doubt that any of them know wwhat they are talking about, to tell the truth.
But I ask you all to take a look and post a couple of things just to give some new blood, so to speak. Also, Facebook has a page called The Hollow Earth Connection and Hollow Earth.