The Clashing Rocks — the Symplegades
Also called: Symplegades, Cyanean Rocks
A legend handed down over the centuries.
A Greek myth told in Book 2 of the Argonautica. At the narrow passage into the Black Sea two rocks crashed together, crushing any ship between them. As Phineus advised, the heroes released a dove first, then rowed through as the rocks parted — and the rocks stood still ever after.

This Greek myth is told in Book 2 of Apollonius’ Argonautica. The Symplegades, two rocks at the mouth of the Black Sea, rushed together across the water and smashed whatever passed between them. When the Argonauts released a dove, it got through with the loss of only a few tail feathers.
As the rocks drew apart again the heroes rowed with all their might, Athena gave the ship a push, and the Argo escaped with the loss of only its stern ornament. It had been fated that if a single ship passed safely the rocks would be fixed for ever, and so they moved no more. Since antiquity the place has been identified with the northern mouth of the Bosporus, where it meets the Black Sea.