Subternia - Hidden Land Beneath the Horizon
Below the crust of planet Eternia lies a hidden hollow globe filled with magical secrets and mysterious races. At the very center of the planet rests the Star Seed, a manifestation of the very magic of the creator gods, forever guarded by their servant Procrustus. It's powers flow through several thin tunnels, culminating at the base of both Central Tower and Castle Grayskull, supplying these mighty monuments with great magical powers. Even before the Three Towers were raised to the surface, many different races fought for dominion over the underground realms including the mighty Caligars and the bat-like Spalians. Eventually Randor's new Council of Eternia helped the warring subterranean races make peace. But the ever present Star Seed and the hidden temple of Serpos have often called both good and evil warriors to battle throughout Eternia's hollow interior!