The Grotto

The Grotto

A blue cave pool tunnelled to the sea, Saipan's signature dive

⚠ Don't swim in alone

Hours

Always open (go in daylight)

Tickets

Free to look, as far as reported; diving and snorkelling are paid through operators

Address

End of Grotto Drive, north of the Bird Island lookout; steps lead down from the car park

A long, steep flight of steps from the car park drops you into a huge pool under a half-collapsed limestone roof. Several tunnels below the waterline open to the ocean, so sunlight leaks in and the water glows an almost electric blue. With each swell the surface rises and falls like it's breathing. Among divers it's the first name people say about Saipan, and dive groups were still going in as of October 2026.