Poʻipū
A marine geyser where ocean swells force water through a lava tube and shoot it 3–9 meters into the air, accompanied by a deep hissing roar. The height and frequency depend on swell size — bigger surf equals a more dramatic show. A second smaller hole alongside produces an eerie moaning sound; local legend holds it is the cry of a giant lizard trapped inside the lava centuries ago. A quick 30-minute stop that punches well above its time investment — it tends to surprise visitors who expected something minor.
Free, no reservation. Located at Poipu Rd at the end of Lawai Rd near Spouting Horn Beach Park. Small free parking lot. Combine naturally with Poipu Beach or Allerton Garden nearby.
More impressive during moderate swell (3–6 feet) which amplifies the geyser. Dangerous to approach the edge when surf is high. Best in morning before vendor carts set up.