On the southern coast, the marble quarries at Alyki were worked continuously from the 7th century BC through the Byzantine period — a span of nearly 1,400 years. The quarried blocks were loaded directly onto ships from the water's edge, and the loading ramps cut into the rock are still clearly visible, dropping straight into the sea. The setting is remarkable: brilliant white marble meeting deep blue water, with cut faces and abandoned blocks scattered along the shore as though the workers simply walked away one afternoon and never came back.
There are also two small Byzantine chapels built from quarry spoil nearby, their walls filled with the same distinctive white stone. Alyki doubles as a swimming spot — the water around the marble shore is exceptionally clear. No facilities, but it is worth the drive south from Thassos Town and easy to combine with a swim at the nearby marble beach at Saliara.