The ESO infrastructures at Chile are:
La Silla Observatory:ESO operates three telescopes: 2.2 m and 3.6 m in diameter and one NTT telescope. La Silla also houses European telescopes that are not operated by ESO, such are the 1.2 m Swiss telescope, which has a high resolution optical spectrograph very useful for detecting exo-planets, and the 1.5 m Danish telescope.
Paranal Observatory: the ESO Very Large Telescope (VLT), at Cerro Paranal, (II Region of Chile), is the most powerful and advanced astronomical complex on the planet. The observatory has four reflective telescopes of 8.2 m. in diameter, which can be used individually to observe objects 4 billion times weaker than what we see with the naked eye. The VLT has also four mobile auxiliary telescopes, of 1.8 m. in diameter, which can travel along the platform on rails.
Llano de Chajnantor: at II Region of Chile, 5,100 meters high and one of the best places in the world for radio astronomy, there is the pioneering experiment of Atacama: a 12 m in diameter antenna, known by its acronym in English, APEX. This project is operated by ESO in Chile and is funded by the Max-Planck Institute (Germany), the Onsala Space Observatory (Sweden) and ESO. The APEX antenna is located at Llano de Chajnantor, the same place where the Atacama Large Millimetre/Submillimetre Array (ALMA) is being constructed.