Ang Thong National Marine Park is an archipelago of 42 karst islands in the Gulf of Thailand characterized by hundreds of millennia-old limestone monoliths rising from the ocean. It spans over 102 square kilometers, and the iconic limestone pinnacles shelter powdery beaches, cliffs, myriad birds, monkeys, dolphins, and tropical jungles. Emerald Lake and Lotus Caves are must-visit spots for diving and snorkeling.