A property combining outstanding cultural and natural characteristics. Its archaeological record extends to 166 BC, with some of the earliest evidence for agricultural settlements in southern Mesoamerica. During the late Classic Period (600-900 AD), a regional center of the Cotzumalhuapa culture was located here, being the easternmost extension of this ethnic group. These and other prehistoric peoples exploited the rich natural resources available from the highly varied environment compressed into a narrow coastal fringe, including sand beaches, mangrove forests, alluvial plains, and volcanic highlands. The highland sector (El Imposible) preserves the largest extant forest in El Salvador.