The Ha'amonga Trilithon located at a far eastern village of Niutou'a from where the first Tongan kings ruled. Affectionately known as 'Stonehenge', the trilithon consists of two large vertical uprights (each about 5 metres high) and a horizontal lintel connecting stone (5.8 metres long) and has a unique astronomical significance. Built by the 11th Tu'i Tonga, Tu'itatui, it dates from around 1200AD. The two uprights represent his sons and the uniting lintel represents the bonds of brotherhood. It was these brothers who moved the centre of goverment to Lapaha where there was a more calm anchorage site for their great double canoes.