Kastro, Greece offers 3 beaches perfect for sunbathing, surfing, swimming, and more. Kastro, Peloponnese, Greece, is known for the Chlemoutsi Castle, a well-preserved medieval fortress offering panoramic views of the surrounding landscape. The best time to travel to Kastro, Greece, is from May to September, with average air temperatures ranging from 75-85°F (24-29°C) and water temperatures around 73-79°F (23-26°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!