Castle Island
Castle Island is a peninsula in South Boston on the shore of Boston Harbor. In 1928, Castle Island was connected to the mainland by a narrow strip of land and is thus no longer an island. It has been the site of a fortification since 1634, and is currently a 22-acre recreation site and the location of Fort Independence. (From Wikipedia ) Phone: 617-727-5290. Here is their website. Trail Map According to AllTrails the trails are paved, about six feet wide in gentle terrain.
Thank you to Mark Dionne for bringing Castle Island to our attention.
Castle Island Loop 0.79 mile