Cimmeria, birthplace of Conan, is an unremittingly somber land, "all of hills, darkly wooded, under skies nearly always gray, with winds moaning drearily down the valleys". The people are the direct descendants of vanished Atlanteans. They are tall and powerful, with dark hair and blue or gray eyes. Cimmerian tribes existe contemporaneously with Atlantis, intermarrying with Atlantean colonists on the Thurian continent prior to the Cataclysm.
Cimmerians of Conan's time are apparently still in a hunting and gathering culture, living in villages deep in the humid forests. The people use iron weapons and have borrowed other elements from the higher cultures to the south. The Cimmerian's chief god is Crom, who takes no interest in human affairs.
Conan is a maverick Cimmerian, one of the few to venture out of the sopping woodlands. The Saga mentions no other Cimmerians living among the advanced nations.
References: Hyborian Age I-II, Phoenix on the Sword, Conan the Valorous, et al.