Mount St. Helens

Mount Saint Helens has a ery important role in the series. As the Olympians move westward, Mount Saint Helens replaces Mt. Etna as the resting place of the Monster Titan Typhon. Though he remained dorment for millenia, the seal binding him began to weaken during Kronos's rise to power. When Percy Jackson and Annabeth Chase investagated the mountain of Hephaestus, they located a group of Telekhine forging the Blade of Kronos's sythe. Percy then called on the power of the sea and caused the mountain to erupt. This weakened the seal on Typhon's prison and lead to a reaction within the mountain that awakened him.