Mount Diablo is a mountain in San Francisco near the Bay Area (3,849 feet). It is where the goddess Athena trapped Enceladus a millennia ago after the first Gigantomachy.

The Heroes of Olympus

The Lost Hero

Gaea freed Enceladus from Mount Diablo, and Enceladus uses the mountain to imprison his enemies like Tristan McLean. Jason, Leo, Piper, and Coach Hedge went to Mount Diablo to free Piper's dad. Jason killed Enceladus with the help of Zeus and re-trapped him in the mountain.


  • The Native Americans of the area lost a battle against the Spaniards there earning the mountain its name, the Devil Mountain (in Spanish). It is considered a cursed yet holy place for them. The Natives that used to live there are the Chumash.
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