The Blue Hole

　　       Introduction
　　       The Blue Hole is situated at the northeastern corner of Saipan Island. It is a natural cave connected to the Pacific Ocean and has been ranked by Scuba Diving magazine as the world’s second-best cave diving site. From the outside, the Blue Hole resembles a dolphin with its mouth open, while inside lies a massive karst cave formed through the erosive action of seawater. The shadows cast by the rocks attract a rich variety of underwater life, including colorful tropical fish, turtles, manta rays, dolphins, jellyfish, sea urchins, and more—the underwater world here is even more vibrant and diverse than that on land. Inside the Blue Hole, there are two natural swimming areas connected to the outer ocean via underwater passages. For experienced deep-sea divers, this offers an unparalleled experience. Due to tidal influences, the water inside the cave can be calm at times and turbulent at others, so extra caution is advised when swimming or diving. Additionally, the concrete steps leading down to the Blue Hole are steep and slippery, so it’s best to walk slowly.

　　        Tinian & Saipan, Saipan Island