THE ARIMPHAIOI (or Arimphaei) were a tribe of long-haired Skythians who dwelt in the cold forests of the north. Like their neighbours the Hyperboreans, they were a sacred race blessed by the gods.
They may be the same as the similarly named Arimaspoi (Arimaspians) and Arimoi.
Pliny the Elder, Natural History 6. 34 (trans. Rackham) (Roman encyclopedia C1st A.D.) :
"From the extreme north-north-east to the northernmost point at which the sun rises in summer there are the Scythians, and outside of them and beyond the point where north-north-east begins some have placed the Hyperboreans, who are said by a majority of authorities to be in Europe. After that point the first place known is Lytharmis, a promontory of Celtica, and the river Carambucis, where the range of the Ripaean Mountains terminates and with it the rigour of the climate relaxes; here we have reports of a people called the Arimphaei, a race not unlike the Hyperboreans. They dwell in forests and live on berries; long hair is deemed to be disgraceful in the case of women and men alike; and their manners are mild. Consequently they are reported to be deemed a sacred race and to be left unmolested by the savage tribes uamong their neighbours, this immunity not being confined to themselves but extended also to people who have fled to them for refuge. Beyond them we come directly to the Scythians, Cimmerians, Cissi, Anthi, Georgi, and a race of Amazones, the last reaching to the Caspian and Hyrcanian Sea.”
- Pliny the Elder, Natural History - Latin Encyclopedia C1st A.D.