The Phantom Empire - 1935 - 5/10

Oh, man. One of the most absurd serials ever, and mightily entertaining!
The lost civilization of Mu is somehow underneath the Western desert.
More than that, it is underneath Gene Autry’s Radio Ranch.
He and his cowpokes find it, but the Muranian Queen does not want surface dwellers near her kingdom.
Meanwhile, there are the usual villains, greedy land developers who cover Radio Ranch!
All sorts of shenanigans keep Gene and his friends galloping across the sagebrush.
Still, he finds time to sing daily at 2:00.
Did I mention Mu robots wearing metal Stetsons?