The castle of Paleon is located at the western entrance of the modern city of Volos and occupies an area of about 60 acres.

According to studies to date, the settlement was first fortified by emperor Justinian in 551 AD, in the place where ancient Iolkos used to be. It seems that the inhabitants of the neighboring settlement Demetrias, were forced to move there because of fear of raids, mainly by the Slavs, during the early Christian times.

In 1204, after the fall of Constantinople by the Crusaders, Dimitriada was given to the Melissenes, a renowned Byzantine family.

In 1423 the castle of the Paleon fell into the hands of the Ottomans. Then the Christian inhabitants began to leave the coastal areas and migrate to the Pelion highlands. The walls survived until 1889, when a large part of them was demolished. The eastern and western sides are preserved to a height of up to 7 meters, and large sections have been excavated. The present city of Volos began to be built outside the old castle shortly after 1830, and its favorable geographical location, due to the port, contributed to its development into an economic center of Thessaly.

In the Paleon district and in the underground garage of the Village cinema complex, one can admire the impressive Roman baths, highlighted by the archaeological service.

In 1958, the site was fortunately designated by law as an archaeological site, and thus managed to retain its character. Many remarkable old buildings, which survived earthquakes and wars, are preserved today and have various cultural and entertainment uses.