Elak Of Atlantis by Henry Kuttner

Set in a vividly imagined prehistoric Atlantis, the book follows a bold young warrior-adventurer who confronts sorcery, monstrous sea-spirits and rival chieftains while pursuing honor, survival and mysterious artifacts; the linked tales mix fast-paced sword-and-sorcery action with eerie supernatural menace and political intrigue amid ruined temples, storm-swept coasts and shadowed jungles, emphasizing daring exploits, narrow escapes and the hero’s gritty resourcefulness.