On Paranal ESO operates the ESO Very Large Telescope (VLT) with four 8.2-m telescopes (the Unit Telescopes or short UTs). Each UT provides one Cassegrain and two Nasmyth focus stations for facility instruments. One Nasmyth focus is available for visitor instruments. In addition each UT is equipped with a Coude focus station from which the light can be coherently combined in the interferometric focus.
ESO also operates four 1.8m Auxiliary Telescopes (ATs), that are used as an interferometric array (VISA).
Currently, 11 instruments including 2 interferometric instruments are operational and offered for science observations. Furthermore, two survey telescope are being operated: the 4-m infrared VISTA, and the 2.5-m visible VST.