Oz

S3, E16: "It's Not Easy Being Green" (flashback)
S3, E20: "Kansas" (flashback)

Oz is a magical world featured on "ABC's Once Upon a Time".

History

Oz is divided into the North, the East, the West and the South, as well as the Emerald City, which is the capitol that resides at Oz's center. Oz is home to many magical creatures, such as Flying Monkeys, Scarecrow, Cowardly Lion and witches (before they were banished from Oz by Zelena). At Oz's center is the seat of power, the Emerald City, from which Oz's reigning ruler commands. A road composed of yellow bricks winds throughout the land, with all branches of it merging at the Emerald City.

Oz is famous for its frequent occurrence of random tornadoes that can carry people and objects to Oz.

Its ruler was the Wizard of Oz, until the Wicked Witch of the West overthrew him and took over. After the last curse is cast, Oz is merged with all the realms of story to be United Realms.

Locations

Emerald Castle
Gingerbread House (Oz)
Ivo's Cottage
Munchkin Village
Woodcutter's Cottage
Yellow Brick Road

Ways to Access Oz

By a natural cyclone.
By Jefferson's Hats' portal of doors where the green curtain door leads to Oz. It is distinguished by the word "OZ" painted in golden letters on each side of the door.
Also, every other way that can be used in a magical location is possible due to the location being a magical world.