The southeast portion of The Big Island is known for its volcanic activity. Often referred to as the Lower East Rift Zone, this is the part of the island that sees lava flows and eruptions from both Mauna Kea and Kilauea. And Ahalanui Beach Park takes advantage of all this thermal activity.
Here, in the southeastern portion of The Big Island, you can swim in a pool that is heated naturally by thermal vents. The water in the pool stays a balmy 90 degrees all year round, but the water temperature may be a bit cooler from time to time.
The water level of the pool makes it safe for families and an invigorating swim. It never gets too deep, and you can always stand up on the soft bottom which is made of mud and sand. And the heated water does wonders for aches and pains. It's a great place to relax after a challenging hike.
This heated pool is all about safety. There are easy ramped steps that take you down into the water, and there's even a lifeguard on duty. And you can ask the lifeguard yourself. There's never been a serious incident down at Ahalanui Beach Park.
The pool is connected to the Pacific Ocean by a small inlet. This inlet lets small tropical fish into the pool, but it keeps the waves at bay. There is never any current in this unique water feature which makes the entire beach park incredibly safe.
The water does smell of sulfur as it is heated by thermal activity. And you should not enter the water here if your have an open wound. The beach park was closed in 2013 when a man came down with a serious infection after entering the water with an open wound. The water temperature allows certain bacteria to thrive, and those bacteria can cause an infection if allowed to enter the body through a cut.
Unfortunately, this beach park has closed due to volcanic activity. A lava flow entered the pool in July of 2018. Predicting lava flows can be difficult, so the pool may be closed permanently, though there is a chance for a future rebuild.