A pair of caves halfway up the south flank of Mount Kerkis where, legend holds, Pythagoras took refuge from the tyrant Polycrates of Samos. The story is medieval rather than ancient, but the location is stunning: a steep path past olive terraces leads up to two openings in the cliff, with a small rock-cut chapel of Panagia Sarantaskaliotissa wedged between them.
The walk up from the trailhead near Marathokampos takes around twenty minutes, much of it on stone steps. The view from the chapel terrace runs across the western flank of the island to the Aegean and on a clear day to the mountains of Ikaria.