An awesome opening in farmland far from the sea. A cleft known to the Maori as Opito (the navel), it plunges some 60 metres down to the water, its perpendicular sides of solid rock fringed with fern. The sea rushes in to the bottom of the pit through a subterranean tunnel about 200 metres in length. Before the bush was cleared the blowhole could be located only by the thunderous booming of its imprisoned waters, appealing to Dr Hocken as 'a huge grave in the forest'. 10.5 km. Signposted. Access is from the southern end of Jacks Bay Rd. Follow the marker poles across farmland to the blowhole, which is reached after an easy 30-min walk. No access during lambing from late September to mid-October. The blowhole is to the left, fenced off for safety, partway up the hillside. It is at its most impressive in heavy weather and at high tide. A little farther on from the blowhole is Penguin Bay, where penguins come ashore in the late afternoon to nest in the forest.