The most important archaeological site in Costa Rica, Monumental Nacional Guayabo, located on the slopes on the Turrialba Volcano, has been recognized as a World Engineering Heritage site. The recognition comes from the U.S. Association of Civil Engineers, one of the most prestigious engineering groups in the world.  The site was chosen for its engineering achievements, specifically for the road, or calle de acceso, and its aqueduct.  These marvels of ancient engineering were completed by the pre-Colombian natives that occupied the land between 700 B.C. and 1,400 A.D.  Olman Vargas, director of the Colegio Federado de Ingenieros y de Arquitectos de Costa Rica (CFIA), commented in La Nación that the road is amazing due to the fact that the natives included retention walls and also for the gentle slope that they build into the road that adapts well to the conditions of the land.  The ancient aqueduct was the other principal reason the site was recognized, with its tank made of stone and system of distribution, also completely made of stone.  Vargas explained that the honor didn’t simply “fall from the sky” and that the CFIA had fought hard for the site to be recognized.  Hopefully, this will bring more world-wide attention to the site and enable more measures to preserve it in the best of conditions.