APEX stands for Atacama Pathfinder Experiment. This is a world-class millimetre & sub-millimetre observatory located at the so-called Chajnantor plateau, on the Chilean Andes. This is an ideal place with outstanding weather conditions for this type of observations.
The APEX project is a collaboration among different European partners and hosted in Chile. The telescope has been in operation for more than 15 years and has evolved since its construction and the start of its operations.
Given the experimental nature of the project, a large variety of instruments are available, some of them very versatile and for general use, and some other more experimental. These, in combination with the excellent weather conditions at the site, enable many astronomers in the world to get the data they need to conduct their research on a variety of astronomical topics.