The highest mountain in Polynesia and a dormant volcano on north-central Hawaii Island. It has very extensive prehistoric basalt adze quarries, mostly between 3350-3780 m (12,400 feet) above sea level. The sites include workshops, rock shelters, stone-walled enclosures, and religious shrines. Radiocarbon dates from the shelters range from 1400-1650 AD. The dome of the volcano is 30 miles (48 km) across, with numerous cinder cones, and is the site of a major astronomical observatory.