Cerro Armazones (3000m), where work has started to build the largest telescope ever.. E-ELT,

ESO's European Extremely Large Telescope (40m diameter mirror!).

Cerro Chajnantor (5100m), where ALMA is already working observing the cold invisible universe in the mm and sub-mm wavelength using 66 antennas (12m and 7m diameter).

Cerro Paranal (2800m), the four 8.2m diameter optical telescopes making ESO's VLT Very Large Telescope, the most powerful and advanced in the world.