Pachat'aqa

{{short description|Archaeological site in Bolivia}}

{{Infobox ancient site

| name = Pachat'aqa

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| image = Gradería de piedra entrada Horca del Inca.jpg

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| caption = Steps at the entrance to Pachat'aqa

| map_type = Bolivia

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| coordinates = {{coord|16|10|18.3|S|69|5|6.7|W|display=inline,title}}

| location = Bolivia, La Paz Department, Manco Kapac Province

| region = Andes

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Pachataka (also spelled Pachataca or Pachat'aqa), commonly known as the Inca Gallows,{{cite web |url=http://www.bolivia.com/empresas/cultura/Sitios_Arqueologicos/isla_sol.asp |title=Isla del Sol|publisher=Viceministerio de Desarrollo de las Culturas |access-date=16 April 2014 |archive-date=22 February 2014 |archive-url=https://web.archive.org/web/20140222225205/http://www.bolivia.com/empresas/cultura/Sitios_Arqueologicos/isla_sol.asp }} is an archaeological site in Bolivia, located near Lake Titicaca in the municipality of Copacabana, Manco Kapac Province, within the La Paz Department.

Pachataka is a pre-Inca astronomical observatory formed by a lintel made of two parallel stone blocks. It was used to determine the seasons, track lunar movements, and predict eclipses.{{cite web |url=http://www.lageoguia.org/la-horca-del-inca-pachataka-copacabana-bolivia/ |title=The Inca Gallows |access-date=8 February 2015 |archive-date=2 April 2015 |archive-url=https://web.archive.org/web/20150402100754/http://www.lageoguia.org/la-horca-del-inca-pachataka-copacabana-bolivia/}} It is located at the summit of Mount Kesanani, approximately 600 meters south of the town of Copacabana.

In the Aymara language, “Pachataka” means “the place where time is measured.” The Spanish mistakenly named it the "Inca Gallows."{{cite web |url=http://www.bolivia.com/empresas/cultura/Sitios_Arqueologicos/horca_inca.asp |title=Pachataka or "Inca Gallows" |author= |publisher=Viceministerio de Desarrollo de las Culturas |access-date=4 March 2015 |archive-date=23 September 2015 |archive-url=https://web.archive.org/web/20150923193527/http://www.bolivia.com/empresas/cultura/Sitios_Arqueologicos/horca_inca.asp}}

According to mathematical and astronomical calculations conducted by the Institute of Cosmic Physics of Bolivia, the observatory dates approximately to 1764 B.C., during the era of the Chiripa culture.

File:Copacabana Bolivia desde la Horca del Inca.jpg|Copacabana and Lake Titicaca as seen from Pachat'aqa