Blue pool
At the bottom.
Abasaa — Public domain · Abasaa — Public domain · tata_aka_T from Tokyo, JAPAN — CC BY 2.0 · tata_aka_T from Tokyo, JAPAN — CC BY 2.0 · Abasaa — Public domain
The Grotto is a collapsed sea cave on the north-east coast of Saipan, about 13 km in a straight line north-east of Garapan. It is one of the best-known dive sites in the western Pacific and one of the island's standout natural sights. The cave is a wide pit in the limestone, its rim overgrown with green plants, with a long stone stairway descending to a pool of deep blue sea water at the bottom. The pool connects to the open ocean through underwater passages, so swells surge in and the water rises and falls. Underwater, divers swim through passages lit by blue shafts of sunlight streaming through the openings, sometimes seeing fish and turtles. From the top, visitors stand on a viewing platform looking down on the pool, and nearby the coast is lined with rocky cliffs battered by ocean waves. The visit is free; dives are paid trips. The stairs down are steep and slippery, diving here is for experienced divers with a guide only, and do not swim in the pool when the sea is rough.
At the bottom.
Underwater.
Above the cave.
North-east Saipan, Northern Mariana Islands
No, for experienced divers with a guide.
Yes; dives are paid.