As we have seen numerous times over the years when it came to
Castle Grayskull the only canon that seemed to get it right was the
Filmation cartoon, which perched the magical castle atop a bone structure, surrounded by a bottomless abyss. The
Star Comics often just placed the castle on a flat unimpressive dead landscape with no deterrents of any sort; leading to an infamous panel in which
Skeletor attempts to dig under the castle using his
Terror Claws! The UK comic was also fairly guilty of surrounding the castle with uninspired land mass. In this panel from issue sixty-five of the UK
Masters of the Universe comic we see that the castle merely sits atop a raised section of land...
(click on the image to see it at full-size)