Aornis may refer to:
- Aornis Hades, the Thursday Next series character, or her namesake, a fictional tributary of the river Styx.
See also:
- Aornos, the site of the battle fought by Alexander the Great's forces
- Avernus, a volcanic crater in Italy called Aornos by the Greeks, thought to be the entrance to the Underworld.
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The Aornis river is not a river in Hades, nor is it one of the five tributary rivers of the river Styx. As you can see in the Wikipedia articles on Hades and Styx there is no mention of an Aornis river.
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