Roughly rectangular in shape, Oz is divided along the diagonals into four countries: Munchkinland in the East, Quadling Country in the South, Winkie Country in the West, and Gillikin Country in the North. These surround the Emerald City in the center. It is surrounded on all four sides by the Deadly Desert, which helps to protect it from discovery and invasion. It is further protected by a barrier of invisibility erected by Glinda. Oz is the largest country on the continent of Nonestica.
At least some of Oz's infrastructure is made of yellow brick. The general style of architecture varies by country.
Oz is the main location in Oz the Great and Powerful when Oscar Diggs (the Wizard of Oz) came to it. New modifications and details of Oz were made, such as denizens like the water fairies and multicolored creatures or places with crystals or animal-shaped mountains.