Sparta

In The Blood of Olympus, Piper McLean and Annabeth Chase go to the temple of Ares in Sparta to obtain the Makhai, the "heartbeat of the chained god", one of the ingredients of the Physician's Cure, from a chained statue of Ares. There they defeat the giant Mimas, whom Piper kills using a statue of Phobos, meeting the rule that a god and a demigod must cooperate to kill a giant.