Some scattered ruins in one of the most beautiful hills of the island, this of Agia (St.) Anna, remained from the Asklipiion of the 4th century BC, with an external archaic sanctuary dedicated to Pythian Apollo, built of Parian marble. The access is via the peripheral road of Parikia, heading south, where you will find the walls at the foot of the hill. Look out for the hidden sign in front of the sanctuary. The stone stairs that will lead you to the ancient site might be a bit tiring, but the view of the blue Aegean will reward you.