Gary S. Cross, professor of modern history at Pennsylvania State University, writes that Castle Grayskull is emblematic of the making of a boy-man culture beginning in the 1980s.
A large skull decorates the front, with a hinged "Jawbridge" allowing access to the interior, through the "mouth" opening.
According to the original storyline, the Sorceress (as she is called in the very first minicomic "He-Man and the Powersword") had split the sword into two and scattered the pieces, in order to protect the castle and its source of universal power.
[11] The original concept art and prototype show a large swamp surrounding the castle, which was going to be printed on a playmat that would be positioned beneath the playset.
[citation needed] The castle was user-friendly, possessing many settings and functions suitable for the 5" action figures it was built to complement.
One day, the elders saw a vision of a beautiful woman dressed in snake armor who warned of future danger and also the coming of He-Man.
The Elders then magically transformed the Hall of Wisdom into Castle Grayskull in order to frighten away intruders and protect the orb.
In the original television series, Castle Grayskull is a legendary/mythical location situated on a pedestal of bones jutting out of an abyss in a barren plain just on the edge of the Evergreen Forest.
It serves as home to the Sorceress and to the mysterious and rarely seen Spirit of Grayskull, as well as a place of refuge for He-Man and all those considered his friends.
[13] Although it is mostly viewed from the outside, there are a few notable internal locations: the Throne Room; Main Chamber (including the Walkway of the Elders); the Hall of He-Man; the Portal Chamber (in the skull top); a laboratory (basement); Mirror Room (basement); the Sorceress' den (where she studies and practices spells; in the right tower); and, the Sorceress' bed-chamber.
In the episode "Double Trouble", an evil doppelganger of He-Man's friend Kol Darr also comes across the chamber that houses the Secrets of Castle Grayskull.
The first image of it seen is of its interior as Skeletor, victorious at last, makes the long march across the castle's Throne Room.
This foundation is formed in such a way that there are four large holes of sizes that altogether occupy most of the floor's area leaving a few wide catwalk walkways.
According to the film, it houses a giant circular portal called "the Great Eye of the Galaxy", which only opens when Eternia's moon reaches its zenith, granting whoever stands before it god-like power.
It is never explicitly stated, though visuals strongly indicate, that for this to happen the Sword of Grayskull must be inserted into a small column near the portal.
Once made of white marble, and at the center of King Grayskull's bustling kingdom, the castle fell into a state of disrepair following a devastating battle with the forces of Hordak.