- Grayskull Tower, which contains the power of good, the toy can be attached to Castle Grayskull, providing it with a prison.
- Viper Tower, which contains the power of evil, the toy can be attached to Snake Mountain and includes a sort of periscope.
- Central Tower, or Eternia Tower, which contains both good and evil powers.
The Three Towers were constructed by the Elders of Eternia to balance the powers of good and evil, thus containing the ultimate power. The Three Towers first appear in the minicomic "The Ultimate Battleground!", when Skeletor and King Hiss summon them from the depths of Eternia. Skeletor enters in Central Tower and acquires enormous powers, but He-Man arrives, also acquires power, and defeats Skeletor. After that comic, King Hiss makes Viper Tower his base, and uses its power to summon his lost warriors, Sssqueeze and Snake Face. Most of the later minicomics show Central Tower as the most important "power fortress" in Eternia, more so than Castle Grayskull. In the minicomic "The Search for Keldor", The Sorceress discovers that the Towers' mere presence in Eternia allows her to leave Castle Grayskull in her human form, without becoming Zoar. Later, in the minicomic "Enter: Buzz-saw Hordak!", Central Tower's power changes Hordak's powers, transforming him into Buzz-saw Hordak. During that comic, Hordak claims he helped to build Central Tower, and states that the Towers have the power of time travel. The last minicomic, "The Powers of Grayskull: The Legend Begins!", shows He-Man and the Sorceress using that power to travel to Eternia's past.
In the Star comics, the Three Towers are much less important. Viper Tower is merely a telescope built by Skeletor, Central Tower is just mentioned as an Eternian palace, and Grayskull Tower is not shown. Since the Towers are not as powerful as in the minicomics, the Sorceress is shown unable to leave Castle Grayskull in her human form, but only as Zoar the falcon, and Hordak acquires his Buzz-saw powers by stealing blueprints from Man-At-Arms' laboratory.