The ruined castle is named after St Hilarion, a hermit monk who fled from persecution in the Holy Land. Originally the castle was built as a watch tower to give warning of approaching pirates around the 7th-10th centuries. In 10th century, the Byzantines built the church and monestary here. Amazingly, much of the castle remains, but you have to climb to see it! After a strenuous climb, the views fron the top of St Hilarion are spectacular. Start early, take a bottle of water and a hat.