Camp Half-Blood is a Greek demigod training facility located on Long Island Sound. The camp is run by Bacchus in his Greek aspect (Dionysus), whom the campers call "Mr. D"; Chiron the centaur is the activities director, couterparted to Lupa the wolf goddess. Camp Half-Blood is also the Greek counterpart of Camp Jupiter, a Roman demigod camp near San Francisco, California.
The camp has magical boundries, which are enhanced by the Golden Fleece; it was found by Grover, Tyson, Percy Jackson, Clarisse La Rue, and Annabeth Chase. The fleece was stolen from Polyphemus' island, and draped over Thalia's pine tree, ensuring that no monsters could get into the camp, without permission. The Fleece stays on the tree, guarded by the dragon Peleus, who sleeps wrapped around the trunk.
Camp is considered to be only safe place for half-bloods, although in the Heroes of Olympus series it is revealed that there is a similar camp for Roman demigods – Camp Jupiter.
The demigods live in cabins (one for each Olympian god or goddess); later, many more cabins were added for minor gods and goddesses because Percy's request in The Last Olympian. The campers all eat at the dining pavilion. There is also an archery field for shooting practice, a sword fighting arena for swordplay, a climbing wall with lava for an 'extra challenge', an amphitheater, stables for pegasi, an armory, and the Big House, where Chiron has quarters and the Camp meetings are held.
The camp's cover name is Delphi Strawberry Service, a reference to the Oracle of Delphi. Camp Jupiter's equivalent of the Oracle is Octavian, who has the gift of prophecies and a descendant of Apollo.
- Camp Half-Blood is mentioned, in every Percy Jackson and Olympians and Heroes of Olympus book, so far.
- Camp Half-Blood was on the Union side of the American Civil War, fighting the Roman demigod Confederates.