The Aleen Underworld was the subterranean wilderness of the planet Aleen. The Kindalo species thrived in the unique atmosphere of the Underworld, and also served as the domain of the strange being called Orphne.
The Underworld of Aleen formed early in the planet's history as the arbozoic trees evolved and took root in the planet's crust. A species with an expansive root system, arbozoic trees died and left behind massive caverns in the upper crust of the planet where a unique atmosphere formed and the Kindalo began to inhabit the ecosphere. The Great Seal was installed by the Aleena to symbolically close off the Underworld to the surface dwellers as a compact between the two races of the world. Because of the tectonic activity, the separate atmospheres of the planet confused planetologists from the Galactic Republic and later the Galactic Empire.
The government within the Underworld was unique to the Kindalo. Practicing a type of absolute consensus, the Kindalo required all members of their species to vote on matters of import in order to take action. Action required a unanimous agreement by all members of the society, which caused xenobiologists and political theorists from offworld to speculate that the Kindalo species was extremely small. The Underworld was also home to the mysterious being called Orphne. Encountered rarely by visitors throughout the planet's history, Orphne resided within her own domain within the Underworld.
- Star Wars: The Clone Wars – "Mercy Mission" (First appearance)
- Star Wars: The Clone Wars – "Nomad Droids" (Appears in flashback(s))