Tonga'?s Stonehenge is a coral rock stone arch, whose name means "Maui's burden" -- the Polynesian God is thought to have carried it like a yoke. It dates from around 1200AD and may once have been the entrance to a palace. It has similarities to Stonehenge as an astronomical site, too: a "V" on the lintel aligns with the rising sun at the summer and winter solstices.