The cave of Aghia Sofia is situated at less than 2 kilometres after the village Topolia, on the road leading from Kastelli to Elafonissos. A short path gets the visitor to the cave and the tiny church of Aghia Sofia within it.

It is found at a height of 285 metres; the main hall is of a diameter of 70 metres and of a height of 20 metres. Huge stalactites, more than 5 metres high, and even huger stalagmites decorate the cave. A few fig trees have grown in the cave and the moss on the rocks paint its walls in deep green.

Archaeological surveys in the cave have shown that man has used it since as early as the Neolithic period. Throughout history the cave has been used for various purposes and there are many local legends about it. The most common of them is the popular belief that there is the hoof print of St. George’s horse in the cave; as the locals say it is well visible somewhere on a rock.