The Atacama Pathfinder EXperiment

APEX is a 12 meter radio telescope located at Llano de Chajnantor, 50 km east of San Pedro de Atacama in Northern Chile, at an altitude of 5105 m above sea level.

APEX is a collaboration between Max Planck Institut fur Radioastronomie (MPIfR), the European Southern Observatory (ESO) and Onsala Space Observatory (OSO). Operations are entrusted to ESO.

More informations can be found here.