Wikipedia
Abarimon is the name of a legendary race of people native to a country of the same name. The people of Abarimon had backwards feet, but in spite of this handicap were able to run at great speed. They lived side by side with wild animals and attempts to capture them failed because they were so savage.
They lived in a great valley of Mount Imaus (now called the Himalayan Mountains). There was a special quality of air which meant if it was breathed for a long period of time it would be impossible to breathe any other type of air and the inhabitants could never leave the valley alive.
The Abarimon people were first described by Pliny the Elder in his book, Natural History (VII 11). A similar tale is recounted by Aulus Gellius in Attic Nights.