The vast majority—47 of the World Heritage Sites studied—were found to be potentially threatened by coastal erosion or storm surges by the end of the century. Specifically, 37 of the sites were found to be at risk from a 100-year flood or storm surge, and 42 to be at risk from coastal erosion. Just two of the sites studied, Medina of Tunis and Xanthos-Letoon, were found not to be facing any risk from either of those two hazards by 2100. – Pacific Standard