Pachat'aqa

Pachat'aqa, also known as the Inca's Gallows, is a pre-Inca astronomical observatory located approximately 600 metres south of Copacabana, Bolivia, near Lake Titicaca. The site consists of two parallel stone blocks forming a lintel structure atop Kesanani hill, used to determine seasons, track lunar movements, and predict eclipses. Dating to approximately 1764 BC during the Chiripa culture period, its name derives from Aymara meaning "place where time is measured". The Cosmic Physics Institute of Bolivia has confirmed the site's astronomical alignment capabilities.