Pan right to the site for the European Extremely Large Telescope E_ELT, a ground_based for the optical near_infrared observations. The E_ELT will have a 39.3_metre_diameter primary mirror, making it the largest optical telescope in the world when it is completed in 2022. It will be built on the top of this mountain, Cerro Armazones, in the Atacama Desert in Chile. With an altitude of more than 3000 metres and being one of the driest places on Earth, it is an ideal site for an observatory.