The melon on the whale bulges towards the blowhole and slopes down towards the beak. Being a toothed whale, pilot whales have a single blowhole. When whales dive under water their nasal plug covers the nasal passage to the blowhole. This fish inhales through its spiracle (blowhole), an anatomical feature present in early tetrapods. The first dead dolphin was found, its blowhole clogged by oil. Odontocetes are known as toothed whales; they have teeth and only one blowhole. One of the main tourist attractions is the Kiama Blowhole. Porpoises, like other odontocetes, possess only one blowhole. Tess finds the treasure in a cave beneath the blowhole. The sounds are made by squeezing air through nasal passages near the blowhole. The formation of a blowhole system begins as a littoral cave is formed. The development of a blowhole is linked to the formation of a littoral cave. This site also contains a geological blowhole, from which wind escapes from a cave system. This is in reference to the Kiama Blowhole which attracts many visitors annually. Both have areas for viewing, though the Kiama Blowhole attracts more tourists.