valley, northeastern Molokai island, Hawaii, U.S. On the northeastern flank of Kamakou summit (4,961 feet 【1,512 metres】), it is a deep, verdant gorge 1.75 miles (2.8 km) long and 0.5 mile (0.8 km) wide. Archaeological evidence dates habitation in the area from c. AD 650, which makes it one of the oldest Hawaiian settlements. The area possesses one of the most complete collections of ancient residential sites, more than a dozen heiaus (ceremonial and religious structures), and a large-scale irrigation system. It is believed to be the longest continually occupied site in Hawaii. In the 13th and 14th centuries, it was one of the most densely populated parts of the Hawaiian Islands. One of the few areas in eastern Molokai suited to agriculture and renowned for the taro root grown there, Halawa Valley supported hundreds of Hawaiians until disastrous tidal waves (1946 and 1957) destroyed most of the buildings and much of the vegetation. It is now occupied by a small number of fishermen and farmers, and it is largely a recreational area (hiking, surfing, fishing). Hipuapua Falls (500 feet 【150 metres】), at the end of the valley, is the area's highest waterfall; also at the end of the valley is Moaula Falls (250 feet 【75 metres】). Legend says the pool below Moaula contains a moo, a giant lizardlike creature.