you are the daughter/son of a god. Olympia is the academy for both heroes (who is descended from lesser gods or characters ex. Medusa, Eris ecc...) or demigods (who descends from a pureblood God ex. Athena, Poseidon ecc...)

as you arrive in the student city of Olympia the sun is shining and you get into your apartment, that you're sharing with three students: River daughter of Poseidon, Beth daughter of Athena and Orion son of Hades

"hey there, welcome to Olympia, I'm River" she says