The Entyrmion was a vast, labyrinthine cavern complex located under the mountain ranges of Skye, a planet in the Outer Rim Territories of the galaxy. The natives of Skye, the S'kytri, regarded the Entyrmion as their underworld, and, as such, it was off limits. According to the , the surface of Skye was originally ruled by chaotic monstruosities, which ended up being locked up in the Entyrmion by the hero Hormaket the Vanquisher.