spouting horn is a blowhole located on the southern coast of kauai in the koloa district. this area of kauai is known for its crashing waves (nearby poipu translates to "crashing"). these waves erode lava rocks on the coastline which can create narrow openings, as is the case with spouting horn. with every wave, water shoots upward when it is forced through an opening and creates a sound suggestive of hissing. the spray can shoot as high as 50 feet in the air.