VLT telescope equipment. FORS (focal reducer and low dispersion spectrograph) apparatus located below the primary mirror (top). FORS1 and FORS2 are central Cassegrain focusing instruments inside the telescopes Antu and Kueyen respectively. These are two of the four 8.2-metre telescopes that make up the Very Large Telescope (VLT) at Paranal Observatory in Cerro Paranal, Chile. The other two are Melipal and Yepun. The images from these telescopes combine to produce an image equal to that obtained by one 16 metre diameter mirror, making the VLT one of the most powerful telescopes in the world. The VLT is operated by the European Southern Observatory. It is at an altitude of 2600 metres in the Atacama Desert, one of the driest places on Earth.