Mauna Kea, Hawaii hosts several telescopes. The most powerful is the W. M. Keck Observatory. Keck has 2 telescopes and both have mirrors which are 10 metres wide. 

The Very Large Telescope (VLT) is high up in Chile's Atacama Desert. It is run by the European Southern Observatory (ESO). The VLT is the world's most advanced visible-light telescope. It can see the faintest and most distant objects in the Universe.