The 29 metre high low hill of Magoula that stands on a low (29 meter) hill above the town was once the acropolis of Pyrasos. Pyrasos is scarcely known from historical sources, except that it was an active harbour and featured a famous temple of Demeter and Kore, after which the harbour was later known as Demetrion.
Today there is virtually nothing to be seen on the acropolis; the only excavation which took place on the hill of Magoula, where the acropolis stood, southeast of Nea Anchialos, proves that the site was peopled since the earliest Neolithic period (6th millennium BC) by fishermen and agriculturalists. The acropolis saw its dire destruction when it came under siege by Philip V in the Hellenistic era.