The Chief's Whistle by Michael Anderson
Mapua'a Vaca, translated to "The Chief's Whistle" in English, is a spectacular 4 km stretch of blowholes on the rugged and rarely visited western coast of the main island of Tonga.
Huge swells from Antarctic storms drift north and are compressed into tunnels in the overhanging lava cliffs. The tunnel compresses the water through a small hole at the end and it shoots 300 feet up into the sky. As the water is funneled through the hole it creates a loud 'fwooop' sound that gives the area it's name. This was actually LOW tide at sunset and the blowholes were still spectacular.