The Mortal Realm is where humans and some immortals live. It is set in the time of Ancient Greece, and therefore lacks the technology of the godly realms. The Mortal Realm is where Demeter has chosen to live and run her business Barley Mother, and where Persephone was raised. Hades reveals that he was born in the Mortal Realm, specifically in the region now known as Sicily. Persephone mentions that the Mortal Realm is too warm for snow when she sees it for the first time in the Underworld.
Demeter used to bring spring to the Mortal Realm, before her daughter Persephone took over. Hades explains how different the two execute spring, and how he prefers Persephone's version.
Locations in the Mortal Realm
Demeter resides on a large plot of land where she grows her crops and operates her business. She employs a large number of nymphs to assist her, and it can be assumed these nymphs also live on her land. This is also where Demeter raised her daughter, Persephone. Persephone rarely left the boundaries of her mother's land.
Psyche is from a human settlement in the Mortal Realm. There is a large Greek temple that dominates this area. Her family are assumed to be wealthy, as she lives in a large home. Eros says that the place is "pretty fancy."
Semele appears to live in a wealthy settlement in the Mortal Realm. A large temple structure, where a party is held, appears to be her home. Zeus, Poseidon, and Hades come to the party disguised as mortals so that Zeus can visit Semele. Hades end up finding an abused dog and takes her home.
Sicily is the area where Hades was born, however at the time it had no name.
Also known as The Beach, Acheron is where the Mortal Realm meets the Underworld. Newly deceased souls are deposited here and must pay Charon, the ferryman, a single obol to cross into the afterlife. Shades who cannot pay must wait on the shores of Acheron for 100 years. The Titan Styx resides here.
Unspecified locations in the Mortal Realm.