The Petralona Cave is a long, multi-chamber limestone cavern in the inland foothills of Halkidiki, west of the main road south from Thessaloniki. Inside, an array of stalactites and stalagmites in pastel pinks, oranges, and whites runs through chambers that take about an hour to walk through with a guide.
The cave is famous chiefly for the Petralona Skull, found fused to a chamber wall in 1960 and one of the oldest hominid skulls ever found in Europe. A small but well-presented museum on site interprets the find and the rest of the cave's prehistoric finds. English-language tours run several times a day.