Mongsanp'o haesuyokchang, South Korea offers 1 beach perfect for sunbathing, surfing, swimming, and more. Mongsanpo Haesuyokchang, Chungcheongnam do, South Korea, is known for Mongsanpo Beach and Taean Haean National Park. The best time to travel to Mongsanp'o Haesuyokchang, South Korea, is from June to August, with average air temperatures around 25-30°C (77-86°F) and water temperatures around 22-26°C (72-79°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!