The way to the Chajnantor plateau

The ALMA site seen from the Atacama salt-lake, located at an altitude of 2300 m, due south from San Pedro de Atacama, in the II Region of Chile. To the right side of the image, the road to the ALMA OSF (Operations Support Facility) is visible. The OSF is located at the fourth curve (counting from the bottom), at an altitude of 2900 m. The ALMA AOS (Array Operation Site) is under construction on the Chajnantor plateau, located behind the mountains, at 5000 m altitude. The combination of high altitude and dryness offers the best conditions possible for ground-based observation of the millimetre and submillimetre radiation, strongly absorbed by the water vapour in Earth´s atmosphere.