The scenic attractions of the Auckland region derive from two main features, the ria-like but extensive Waitemata Harbour, which is superb for yachting, and the volcanic activities of the Tertiary period which has been responsible for the large number of volcanic cones that stand above the general level of the terrain. Rangitoto, the most symmetrical and famous, stands off the North Shore just outside the harbour and as a reserve is preferred by picnickers. The other cones, closer to the city, have been chosen as domains and parks or, worse, as sources of road metal. In general the region in its eastern portion is underlain with rocks of Tertiary age or greywackes. These latter rocks give rise to the Hunua Ranges on the western side of the Firth of Thames from where the city draws its water supplies. In the Pukekohe area is an extensive area of volcanic rock. An important area for market gardening is associated with the fertile soils which are derived from these rocks. On the eastern side of the region, between the mouth of the Waikato River and the entrance to the Manukau Harbour, is a low-lying area of Quaternary deposits given over to rich dairying country. But across Manukau Harbour rise the Waitakeres to 1,580 ft. This ridge is bush covered and offers a pleasant scenic drive, though recently encroachment by housing has been very marked. As this brief sketch of the geology indicates, the land forms and the scenery of the region are quite diverse. In close juxtaposition are rich dairying or market gardening lands, bush reserve and domain, and, in addition, city and suburb, beach and harbour, industry and commerce.