Very Large Telescope (VLT) at the European Southern Observatory's (ESO) site at Cerro Paranal in Chile. The VLT comprises four 8.2-metre mirror telescopes: Antu, Kueyen, Melipal and Yepun. The images from these optical telescopes can be combined by interferometry to give an image equivalent to that obtained by a 16-metre diameter mirror. This makes the VLT the most powerful telescope in the world in 2000. The mirrors are flexible, and are constantly adjusted by computers to compensate for errors. Cerro Paranal has an altitude of 2600 metres and is situated in the Atacama Desert, one of the driest places on Earth. This gives the site excellent viewing conditions.