Mount Olympus

Mount Olympus is a world featured on Once Upon a Time.

Before First Curse
When Kronos becomes the next ruler of Mount Olympus, he is given the Olympian Crystal. ("Last Rites")

After ruling Mount Olympus for many years, Kronos eventually chooses Zeus to be his successor. This results in Hades becoming jealous towards his brother. Hades kills his father and steals the Olympian Crystal and intends on killing his brother too. After finding out Hades' action, Zeus curses Hades by making his heart beating stop. Zeus then brakes the Olympian Crystal into halves. Angered at Zeus, Hades leaves Mount Olympus for the Underworld to become the ruler as Zeus is crowed King of Mount Olympus. ("Souls of the Departed", "Last Rites")

After Helga's death, she ascends to Mount Olympus where she peacefully waits for her sisters to join her. ("The Snow Queen")

Feeling lonely in Mount Olympus, Zeus briefly leaves the land to the Enchanted Forest where he meets a women and have a son — Hercules. Zeus eventually leaves them for home and patiently waits for Hercules to join him in the Palace of Olympus. ("Labor of Love")

After the shipwreck, Gerda ends up in Mount Olympus and reunites with Helga. ("A Tale of Two Sisters")

During Second Curse
TBA Neal's death

After Second Curse
TBA Ingrid's death to Olympus

After Third Curse
TBA Neal leaves Mount Olympus to Dream World to warn Emma

After Fifth Curse
In order to unite all the realms as one, Regina Mills recasts the Dark Curse with a slight variation. The curse spreads into Mount Olympus, ripping everyone and everything, destroying the realm. Mount Olympus then merges with other realms which forms the United Realms. ("Leaving Storybrooke")