Cayo Arena, Puerto Plata. Located on the north coast of the Dominican Republic, Cayo Arena is a small islet off Punta Rucia, about 20 minutes’ journey by boat. Here you get the feeling of being on an island lost in the sea, surrounded by water so clear that you can see small colorful fish that come to welcome you. Unforgettable landscapes will stay in your mind forever. It is ideal for snorkeling.