The Roman equivalent of Camp Half-Blood, located near San Francisco. More militarised and structured than its Greek counterpart, organised into legions with ranks and a Senate. Praetorians govern the camp. Greek and Roman demigods are kept separate to prevent the divine aspects of the same gods from colliding.

The seven demigods of the Great Prophecy who sail on the Argo II: Percy Jackson, Annabeth Chase, Jason Grace, Piper McLean, Leo Valdez, Hazel Levesque, and Frank Zhang. The central ensemble of the Heroes of Olympus series.

The crew assembled for the quest in Heroes of Olympus: Percy, Annabeth, Jason, Piper, Leo, Hazel, Frank, and Coach Hedge. Sail from Camp Half-Blood to Greece and back, fighting gods, giants, and each other's worst instincts along the way.