El Pilar is an ancient Maya city center located on the Belize-Guatemala border. It can be accessed from the Cayo District in Belize, 12 miles (19 km) north-west of the town of San Ignacio, or from the department of El Petén in Guatemala, 30 kilometres (19 mi) north of Melchor de Mencos.
The El Pilar Archeological Reserve for Maya Flora and Fauna, was declared a cultural monument both in Guatemala and Belize, and covers 5,000 acres (2,000 ha), half of which lies in each country. It is jointly managed by the Belize Institute of Archeology (IoA) and Guatemala's Instituto de Antropología e Historia (IDAEH). El Pilar is the largest site in the Belize River area with over 25 plazas, hundreds of other buildings, covering about 50 hectares (120 acres).
Based on ceramic analyses, it is known that monumental constructions at El Pilar began in the Middle Preclassic around 800 BCE. By 250 BCE there were major public works and extensive occupation in the El Pilar area. At its height, El Pilar housed more than 20,000 people. Monumental construction continued with the last major remodeling in the Terminal Classic (1000 CE), after which the monuments were neglected. The name “El Pilar” is Spanish for “watering basin,” reflecting the abundance of water in the area, which is rare for the Maya world.
A major archeological excavation project has been carried out since 1993. However, for conservation purposes most monuments are not exposed. The objective is to selectively and partially expose strategic areas. Today one can see door jambs, walls, and rooms along the wooded trails. This is a style of presentation known as "Archaeology Under the Canopy" that leaves the monuments protected by forest foliage. The only fully exposed monument at the reserve is a house site called Tzunu’un, bringing attention to El Pilar’s unique focus on Maya houses and life ways. El Pilar also features a Maya forest garden to demonstrate traditional agricultural practices.
El Pilar has been under threat by looters and was placed on the World Monument Fund's 1996 list of 100 Most Endangered Sites in the World.
The reserve is open to the public and has a series of trails providing access throughout the site. There is an active initiative to make El Pilar of Belize and Guatemala the first archaeological peace park in the world.