The Aceh Geohazards Project was based at the Earth Observatory of Singapore in partnership with the International Centre for Aceh and Indian Ocean Studies (ICAIOS),  Syiah Kuala University and UIN Ar-Raniry from 2015-2017. The project investigated the interaction of geohazards and human settlement along the coast of Aceh, Indonesia over the past thousand years, combining multidisciplinary approaches of geology, geomorphology, history and archaeology to better understand the past occurrence of tsunami in Aceh, and the extent to which such events might have impacted past societies. Its work traced the evolution of settlements and coastal and river systems through the past millennium via geological mapping, geochronology, geodesy, stratigraphy, micropaleontology, and archaeology to produce a compelling picture of the interaction of humanity and geohazards for the past thousand years along this historically important coast. We found that the immediate predecessor of the 2004 tsunami occurred six centuries ago and devastated 14th century coastal settlements, including the prominent trading port of Lamri.