Cerro Armazones

Cerro Armazones is a mountain located in the Sierra Vicuña Mackenna of the Chilean Coast Range of the Andes, approximately 130 km southeast of Antofagasta in the Antofagasta Region, Chile. The mountain is situated in an ideal location for optical astronomy due to its 89% cloudless nights annually. On 26 April 2010, the European Southern Observatory Council selected Cerro Armazones as the site for the planned Extremely Large Telescope; construction commenced in June 2014. The first light observation is scheduled for 2027.

Prior to ELT construction, Cerro Armazones had an elevation of 3,064 metres, but the resulting plateau now stands several meters lower after the summit was truncated during construction.