Guayabo National Monument, Cartago

Guayabo National Monument is one of Costa Rica's most important archaeological sites, located on the forested slopes of the Turrialba Volcano. These ruins comprise the country's largest pre-Columbian city. This ancient civilization, which is considered to have existed between 1000 BC and 1400 AD, was home to over 10,000 individuals.

Guayabo was discovered in the late 1800s and was thought to be an ancient cemetery. Archaeologist Carlos Aguilar Piedra discovered the stone foundations in 1968. He tried to clear the dense vegetation surrounding the location in order to determine its size. Three aqueducts, 43 stone foundations, two main roadways, several tiny walkways, and tombstones were uncovered.

Early explorers left little trace of the city, and the reasons for its demise remain a mystery.

Location: Cartago, Costa Rica