The Sea of Tartarus is an exclusive location, found within the Underworld. First appearing in the Disney animated film, Hercules, the Sea of Tartarus is a dark, and deepest section of the Underworld, serving as the imprisoment of the Titans, sealed by Zeus, to end their reign of destruction. It is located deep beneath the ocean. At one time, when the planets align, the Sea of Tartarus' opening unviels to show the Titans' existence. It is that the moment, when a challenger, like Hades, uses all of his might to release the Titans from Tartarus, to help him in his collaborate plan of world domination.
While in the first Disney vs. Non-Disney Villains and Disney Villains Wars, the release of the Titans is reminiscent of that of the original movie, in the Disney Heroes vs. Villains and Heroes vs. Villains Wars, the release of the Titans is shown to be caused by the effects of Zurg's, and of the Drej's, technological weapons, respectively.