Hummanaya is the only known blowhole in Sri Lanka and it may be the second largest blowhole in the world.It is located after Matara and Dikwella town in the Southern Province and at small fishing village called Kudawella. There is a rock with a long but narrow fracture in the middle. At once rough sea waves gush through the crack and pass out through the hole at the bottom of the rock and blow out high in to the sky displaying a marvel water fountain.Occasionally the blowhole shoots water several feet above the rock. If sea is rough with strong winds and waves gush fast, the height of the water blow-up goes up 25 metres (82.0 ft) to 30 metres (98.4 ft).