Mnemosyne — Classical Greek Myth Library

Following Phineus’s advice, the Argonauts approached the Symplegades—the Cyanean or Clashing Rocks that guarded the mouth of the Bosporus into the Black Sea (Euxine). The twin cliffs periodically slammed together, crushing whatever was caught between, then sprang apart again. They released a dove (Hera or Phineus’s instruction). The bird flew through; the rocks crashed and sheared off only her tail feathers. As the cliffs rebounded open, Tiphy and the crew rowed with desperate force. In Apollonius, Athena herself holds the rocks apart and thrusts the Argo through; the ship’s stern ornament (or end-beams) is nipped as the rocks close, but the hull clears. Once a ship had passed safely, the oracle of the rocks’ motion was fulfilled: the Symplegades rooted themselves and never clashed again. The Argonauts entered the Euxine and sailed along its southern shore toward Colchis, past further landmarks Phineus had named. Apollodorus gives the same essentials: dove sent ahead; Argo follows as the rocks open; stern-tip sheared; rocks thereafter fixed. The passage is the voyage’s great physical threshold—divine help plus human timing—after which the Black Sea route to Aeetes lies open.