A sea of clouds below the William Herschel Telescope
Due to the location of the island and the height of its mountains, some 2,400 m (7,874 ft) above sea level, a number of international observatories have been built on the Roque de los Muchachos. The particular geographical position and climate cause clouds to form between 1,000 m (3,281 ft) and 2,000 m (6,562 ft), usually leaving the observatories with a clear sky. Often, the view from the top of the volcano is a sea of clouds covering the eastern part of the island. Telescopes at the observatory include:
* The Isaac Newton Group of Telescopes (ING) operates three telescopes: the 4.2 m (14 ft) William Herschel Telescope, the 2.5 m (8 ft 2 in) Isaac Newton Telescope and the 1 m (3 ft 3 in) Jacobus Kapteyn Telescope.
* The 2.5 m (8 ft 2 in) Nordic Optical Telescope (NOT).
* The 1 m (3 ft 3 in) Swedish 1-m Solar Telescope (SST) operated by the Institute for Solar Physics.
* The 0.45 m (1 ft 6 in) Dutch Open Telescope (DOT).
* A 0.6 m (2 ft 0 in) optical telescope.
* The Carlsberg Meridian Telescope (CMT).
* The 1.2 m (3 ft 11 in) Mercator Telescope.
* The 2 m (6 ft 7 in) Liverpool Telescope.
* The 10.4 m (34 ft) Gran Telescopio Canarias (Great Canary Telescope, dedicated
24 July 2009).
* The 3.6 m (12 ft) Telescopio Nazionale Galileo (TNG).
* The 17 m (56 ft) MAGIC Telescope, an air shower Cherenkov telescope for observing high energy gamma rays
* The Super WASP-North telescope, used to detect extrasolar planets.
The DOT and the SST have been specifically built to study the Sun.