In ancient times small fortresses in strategic positions protected the territory from raids and controlled the roads and passes.

Such a fortress is located on the Pyrgos hill west of Pines. Shaped rectangular and built with large megaliths, the fortress dating back to Hellenistic times belonged to the territory of Olous and controlled the road to Driros.

On the walls of the building as well as on rocks around it, male and female names, figures, as well as "traces" (footprints), associated with the garrison stationed there, have been carved.