An extraordinary telescope calls for an exceptional site. Great care was therefore taken to ensure that the home of the ELT was the best possible. This required a high, dry site — perfect for observations.
On 2–3 March 2010, the ELT Site Selection Advisory Committee presented a report to the ESO Council concluding that Cerro Armazones, near Paranal, stood out as the clearly preferred site, because it has the best balance of sky quality across all aspects and it can be integrated with the existing ESO Paranal Observatory. Several possible sites in Argentina, Chile, Morocco and Spain were tested.
Cerro Armazones is a mountain at an altitude of 3046 metres in the central part of Chile's Atacama Desert, some 130 kilometres south of the town of Antofagasta and about 20 kilometres from Cerro Paranal, home of ESO's Very Large Telescope (travel info here).
On 13 October 2011, an agreement was signed between ESO and the Chilean government, including the donation of 189 km2 of land around Cerro Armazones for the installation of the ELT, as well as a concession for 50 years relating to the surrounding area.
On 27 October 2013, the President of Chile, Sebastián Piñera, handed over the signed legal documents by which the Chilean government transferred this land around Cerro Armazones to ESO.
Flying over Cerro Armazones (filmed in April 2018). Download this video in other formats from the video archive.
A Tour of Paranal and Cerro Armazones
Virtual Tour of Paranal and Cerro Armazones.