over time, with the 4.2m William Herschel Telescope opened in 1987, the Nordic Optical Telescope in 1988 and several smaller solar or specialized telescopes; the Galileo National Telescope opened in 1998 and the Gran Telescopio Canarias opened in 2006, with its full aperture in 2009. A fire on the mountainside in 1997 damaged one of the gamma-ray telescopes, but subsequent fires in September 2005 and August 2009 did no serious damage to either the buildings or the telescopes. In 2016, the Instituto de Astrofisica de Canarias and Cherenkov Telescope Array Observatory signed an agreement to host Cherenkov Telescope Array’s northern hemisphere array at the ORM. In 2016, the observatory was announced as the second-choice location for the Thirty Meter Telescope, in the event that the Mauna Kea site is not feasible. Telescopes/observatories The Spanish island is host to the premiere collection of telescopes and observatories from around the World, for the northern hemisphere excluding the Hawaiian islands which has a different mix of telescopes. The 10.4 meter Grand Telescope Canarias is the largest single aperture for an astronomical observatory in the world. Carlsberg Meridian Telescope (1984–2013) Dutch Open Telescope First G-APD Cherenkov Telescope (FACT) (2011– ) Galileo National Telescope Gran Telescopio Canarias (2007– ) HEGRA Isaac Newton Telescope Jacobus Kapteyn Telescope Liverpool Telescope (2003– ) MAGIC MASCARA Mercator Telescope Nordic Optical Telescope Swedish Solar Telescope Wide Angle Search for Planets (WASP) William Herschel Telescope European Solar Telescope (In project) Gallery See also Astronomical seeing Cherenkov Telescope Array Gran Telescopio Canarias IACT Instituto de Astrofísica de Canarias Isaac Newton Group La Palma List of space telescopes (Another important source of astronomical observations in this period) Roque de los Muchachos Teide Observatory References External links Observatory website (English) Current weather and astronomical conditions Panoramic 360 Observatory Travel information MAGIC gamma-ray observatory CTA gamma-ray observatory Astronomical observatories in La Palma