The authors show how sites in upland Hawai‘i may be dated using uranium series radiogenic measurements on coral. The sites lie in a quarry, inland and at high altitude, with little carboniferous material around, and radiocarbon dating is anyway problematic here for the first millennium. Freshly broken coral had been transported to these sites, remote from the sea – no doubt for ritual purposes. Giving a date in the fifteenth century with an error range of only five years, the method promises to be valuable for the early history of the Pacific.