With expanses of blue ocean everywhere, you wouldn’t think that Hawaii would need man-made swimming lagoons. But the ones at Ko Olina, on Oahu’s southwest coast, achieve something improbable on this naturally picture-perfect island: they’re beautiful.

There are four lagoons in total, each of them carved in half-moon shapes, directly into the rocky coastline where swimmers can enjoy mostly waveless, still water, the shade of palm trees, and short stretches of beach and soft grass.

While open to the public, the coastline near the lagoons is home to a series of large resorts, including Disney’s Aulani and a new Four Seasons. The latter was formerly a JW Marriott and is re-opening in June 2016 after a $500 million renovation. Due to high demand, the resort is allowing early reservations for a limited number of dates in 2016. The best part? They’re offering an attractive discount for those who want to experience the property first.

With the introductory offer, which includes a fourth night free, you can stay for an effective rate of $447 per night. The rate is available fairly consistently throughout the travel window, which runs from June to September of 2016, and is good for the hotel’s “Aloha” room, which has a king bed and a furnished balcony. Weekends are included in the offer -- a nice perk. The hotel’s rates without the offer are advertised at $595 per night, for a total savings of $148. Rates at Disney’s Aulani, which is just next door, are hovering around $575 over these same dates.

No code or special link is needed to book. Simply visit the Four Seasons Oahu’s website and look for “Introductory Offer -- Fourth Night Free” when you’re searching for dates in the booking engine.

The property offers some nice options for quiet, relaxation, and privacy, like a pool and beach that are both adults-only, as well as sunrise yoga –--but be sure to wander down to the oceanside pathway to explore those four lagoons.