Guayabo is the nation´s most famous archaeological site. It is thought to have originated around 1,000 BC, thrived between 800 and 1300 AD, and declined thereafter. It was abandoned about 1400 AD. The circular mounds (montículos) here once supported large buildings. Some of the stones in the walkways (calzadas) are decorated with petroglyphs and there´s also a large boulder carved with representations of the crocodile and the jaguar, both indigenous deities. This park also protects the surrounding premontane rainforest, the Guayabo River Canyon of 539 acres (218 ha), where you can walk on a nature trail.