Keratea, Greece offers 1 beach perfect for sunbathing, surfing, swimming, and more. Keratea, Attica, Greece, is known for its proximity to the ancient site of Thorikos and the Lavrio Technological and Cultural Park. The best time to travel to Keratea, Greece, is from May to September, with average air temperatures ranging from 75°F to 85°F and water temperatures around 72°F to 79°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!