Volos is at the centre of the myth of the Argonaut expedition known the world over. The first major naval expedition of the ancient Greeks is directly related to Iolcos, the ruling city on the Pagasetic Gulf during the Bronze Age. It was from here that the ship Argo set off with Jason and the Argonauts for Colchis in the Black Sea (Russian-Georgian border) to claim the Golden Fleece.

Source:   https://www.volosinfo.gr/myths-of-volos-and-pelion/