The Valley of the Lost was an odd Etherian location. Initially it was written to be a place of dread that no one ever returns from, but as the series progresses we see that pretty much anyone can return from the valley. Often thought to be just a misty location this striking image from "The Rock People" shows the valley in all its glory! Not only is this a great composition with the heroes looking out into the distance, but the Filmation background artists prove once again that they can take a description and turn it into something truly magical, if not a little eerie.
(click on the image to see it at full-size)