What is the setting in the novel, The Hour of the Dragon?

When he began writing about Conan, Howard developed an imaginary history and geography of Conan's world. This enabled him to maintain a consistency of setting and events from one story to the next. The events in The Hour of the Dragon are set in an imaginary Hyborian Age, which succeeded a Pre-Cataclysmic Age of the barbaric civilizations of Atlantis and Lemuria. With the coming of the Cataclysm, Atlantis and Lemuria sank into the oceans and the semi-civilized peoples of the world sank back into savagery.