During the island prosperous period (during the 6th century BC), due to the wealth amassed from the exploitation of the mines, the Sifnians started building a network of beacon towers across the whole of the island. The first were close to the mines and they later extended the network to the rest of the island, in farming areas and other strategic locations (hilltops and hillsides). These fortified defensive structures were used both as lookout points and outposts to enable communication within and around the island, and as refuges for the rural population to retreat to when faced with surprise raids from pirates. All the towers on the island were round. They communicated with each other, and with the ancient acropolis citadels using mirrors and smoke signals. Today the archaeological service has recorded the details of 77 ancient towers on Sifnos, that is, more than one tower per square kilometre. Many of them are in remote locations and are more difficult to reach, but there are several that are more easily accessible.
Of those who survive to most of their full height and are more easily accessible, the most outstanding are the ‘Aspros Pyrgos’ (White Tower) at Pantocratora (6th century BC), the ‘Mavros Pyrgos’ (Black Tower) in Exambela (5th century BC) and the tower at Kade on the way to Vathi (4th century BC).
Since 2003, almost two and a half thousand years after they were first put to use, local organisations and dozens of volunteers have revived the communication system of the ‘fryktories’, lighting the beacons once a year on Pentecost Sunday.
Source: www.sifnos.gr