Answer:
You know all those greek mythologys? well that's where olympus comes in...
All the greek gods and goddesses lived in the mortal realm before they lived in olympus, but it's pretty much where all the gods and goddesses live. Only a select few humans can go in, and the demigods can also go in too. The twelve main olympians that live there are Zeus, Hera, Poseidon, Demeter, Athena, Apollo, Artemis, Ares, Hephaestus, Aphrodite, Hermes, and either Hestia or Dionysus.