Gallops Island. (Courtesy Liz Cook/Boston Harbor Now) The Boston Harbor Islands have made it onto an annual list of America’s 11 Most Endangered Historic Places. The nonprofit National Trust for Historic Preservation compiles the the list, which draws attention to historic places threatened by neglect or development. In the case of the Harbor Islands, the risks come from climate change, sea level rise and erosion. More than 300 places have been listed in the 33-year history of the endeavor, and in that time, fewer than 5% of listed sites have been lost, according to the group's website. Past years' lists have included the Gay Head Lighthouse in Aquinnah and the Malcolm X House in Boston.