Antenna foundations for ALMA's Atacama compact array

View of the antenna foundations for ALMA's Atacama Compact Array, at the Array Operations Site (AOS), currently under construction on the Chajnantor plateau, at 5000 metres altitude in the Chilean Andes, some 50 km east of San Pedro de Atacama. ALMA is a single telescope of revolutionary design, composed of a main array of fifty 12-metre antennas and an additional compact array of four 12-metre and twelve 7-metre antennas. ALMA is the largest astronomical project in existence and the most powerful submillimetre-wavelength radio telescope in the world.