List of highest astronomical observatories


This is a list of the highest astronomical observatories in the world, considering only ground-based observatories and ordered by elevation above mean sea level. The main list includes only permanent observatories with facilities constructed at a fixed location, followed by a supplementary list for temporary observatories such as transportable telescopes or instrument packages. For large observatories with numerous telescopes at a single location, only a single entry is included listing the main elevation of the observatory or of the highest operational instrument if that information is available.

History of high altitude astronomical observatories

Prior to the late 19th century, almost all astronomical observatories throughout history were located at modest elevations, often close to cities and educational institutions for the simple reason of convenience. As air pollution from industrialization and light pollution from artificial lighting increased during the Industrial Revolution, astronomers sought observatory sites in remote locations with clear and dark skies, naturally drawing them towards the mountains. The first permanent mountaintop astronomical observatory was the Lick Observatory constructed from 1876 to 1887, at the modest elevation of atop Mount Hamilton in California. The first high altitude observatory was constructed atop the Pic du Midi de Bigorre in the French Pyrenees starting in 1878, with its first telescope and dome installed in 1904. Astronomical observations were also made from Mont Blanc in the late 1800s.
A few other high altitude observatories were constructed through the first half of the 20th century. However, the two most important and prominent of the early 20th century observatories, Mount Wilson Observatory and Palomar Observatory, were both located on mid-elevation mountaintops of about in southern California. The stunning successes and discoveries made there using the world's largest telescopes, the 100-inch Hooker Telescope and 200-inch Hale Telescope, spurred the move to ever higher sites for the new generation of observatories and telescopes after World War II, along with a worldwide search for locations which had the best astronomical seeing.
Since the mid-20th century, an increasing number of high altitude observatory sites have been developed at locations around the world, including numerous sites in Arizona, Hawaii, Chile, and the Canary Islands. The initial wave of high-altitude sites were mostly in the range, but astronomers soon sought even higher sites above. Among the largest, best developed, and most renowned of these high altitude sites is the Mauna Kea Observatory located near the summit of a volcano in Hawaii, which has grown to include over a dozen major telescopes during the four decades since it was founded. In the first decade of the 21st century, there has been a new wave of observatory construction at very high altitudes above, with such observatories constructed in India, Mexico, and most notably the Atacama Desert in northern Chile, now the site of several of the world's highest observatories. The scientific benefits of these sites outweigh the numerous logistical and physiological challenges which must be overcome during the construction and operation of observatories in remote mountain locations, even in desert, polar, and tropical island sites which magnify the challenges but confer additional observational advantages.
Sites at high altitude are ideal for optical astronomy and provide optimal seeing, being above a significant portion of the Earth's atmosphere with its associated weather, turbulence, and diminished clarity. In particular, sites on mountaintops within about of the ocean often have excellent observing conditions above a stable inversion layer throughout much of the year. High altitude sites are also above most of atmosphere's water vapor, making them ideal for infrared astronomy and submillimeter astronomy as those wavelengths are strongly absorbed by water vapor. On the other hand, high altitude does not offer as significant an advantage for radio astronomy at longer wavelengths, so relatively few radio telescopes are located at such sites. At the far end of the spectrum, for the extremely short wavelengths of x-ray and gamma ray astronomy, along with high-energy cosmic rays, high altitude observations once again offers significant advantages, enough that many experiments at these wavelengths have been conducted by balloon-borne or even by space telescopes, although a number of high-altitude ground-based sites have also been used. These include the Chacaltaya Astrophysical Observatory in Bolivia, which at was the world's highest permanent astronomical observatory from the time of its construction during the 1940s until surpassed in 2009 by the new University of Tokyo Atacama Observatory, an optical-infrared telescope on a remote mountaintop in Chile.

Highest permanent observatories

Permanent observatories above 3,000 m:
Observatory NameElevationObservatory SiteLocationCoordinatesEstablishedType of ObservatoryMajor Instruments
University of Tokyo Atacama Observatory Cerro ChajnantorAtacama Desert, Chile2009Optical, infrared
Chacaltaya Astrophysical ObservatoryChacaltayaAndes, Bolivia1946Cosmic ray, gamma ray
James Ax ObservatoryCerro TocoAtacama Desert, Chile2011MicrowavePOLARBEAR
Atacama Cosmology TelescopeCerro TocoAtacama Desert, Chile2007Microwave
Llano de Chajnantor ObservatoryLlano de ChajnantorAtacama Desert, Chile1999Millimeter wave, submillimeterALMA, APEX, QUIET
Shiquanhe Observatory
Shiquanhe, Ngari PlateauTibet Autonomous Region, China2011Optical-
Large Latin American Millimeter Array Alto de ChorillosSalta, ArgentinaUnder ConstructionSubmillimeterLLAMA,
Llano de Chajnantor ObservatoryPampa La BolaAtacama Desert, Chile2002SubmillimeterASTE, NANTEN2
Large Millimeter Telescope Alfonso SerranoSierra NegraPuebla, Mexico2006Microwave
Indian Astronomical ObservatoryMount SaraswatiHanle, Ladakh, India2001Infrared, gamma ray, OpticalHimalayan Chandra Telescope, HAGAR
Meyer-Womble ObservatoryMount EvansColorado, United States1996Optical, Infrared
Yangbajing International Cosmic Ray ObservatoryYangbajainTibet Autonomous Region, China1990Cosmic ray
Mauna Kea ObservatoryMauna KeaHawaii, United States1967Optical, infrared, submillimeterKeck, UKIRT, Gemini North, Subaru, JCMT, CSO, SMA, CFHT
High Altitude Water Cherenkov Gamma-Ray ObservatorySierra NegraPuebla, Mexico2013Gamma ray
Barcroft ObservatoryWhite Mountain PeakCalifornia, United States1976Infrared, millimeter wave
Very Long Baseline Array, Mauna Kea SiteMauna KeaHawaii, United States1986Radio telescope
Llano del Hato National Astronomical ObservatoryLlano del HatoAndes, Venezuela1970sOptical telescope1-m Askania Schmidt camera, a 65-cm Zeiss refractor, a 1-m Zeiss reflector and a 50-cm Askania double astrograph
Iranian National ObservatoryMount GargashIsfahan, Iran2010sOptical telescopeUnder Construction
Sphinx ObservatoryJungfraujochBernese Alps, Switzerland1937Optical telescope
Mauna Loa ObservatoryMauna LoaHawaii, United States1957Optical, millimeter waveMauna Loa Solar Observatory, AMiBA
Magdalena Ridge ObservatorySouth BaldyNew Mexico, United States1999Optical, infrared
Mount Graham International ObservatoryMount GrahamArizona, United States1993Optical, submillimeterLBT, HHST, VATT
Gornergrat ObservatoryGornergratPennine Alps, Switzerland1967Infrared, submillimeterGornergrat Infrared Telescope, KOSMA
Peak Terskol ObservatoryPeak TerskolNorth Caucasus, Russia1980Optical
European Extremely Large TelescopeCerro ArmazonesAtacama Desert, ChileNot completedOptical, near infrared
Haleakala ObservatoryHaleakalaHawaii, United States1964Optical, millimeter wavePan-STARRS, LCOGT Faulkes Telescope North, AEOS
Notre Dame University-Louaiz ObservatoryMount LebanonPeak Al-Znanir, LebanonNot completedOptical telescopeUnder Construction

Highest temporary observatories

Temporary observatories above 3,000 m:
Observatory NameElevationObservatory SiteLocationCoordinatesEstablishedType of ObservatoryMajor Instruments
Receiver Lab TelescopeCerro SairecaburAtacama Desert, Chile2002Submillimeter, 1–2 THz
PLATO Dome AEast Antarctic Ice Sheet, Antarctica2008Optical, submillimeter
Concordia StationDome CEast Antarctic Ice Sheet, Antarctica2005Optical, infrared, submillimeter

Other important high altitude observatories

This is a selected list of the most important and notable high altitude observatories between 1700 and 3000 m; it is not intended to list all of the numerous observatories worldwide in this elevation range:
Observatory NameElevationObservatory SiteLocationCoordinatesEstablishedType of ObservatoryMajor Instruments
Sierra Nevada ObservatorySierra NevadaGranada, Spain1981Optical
Pic du Midi ObservatoryPic du Midi de BigorrePyrenees, France1878Optical, solar
Amundsen-Scott South Pole Station /
Martin A. Pomerantz Observatory		South PoleEast Antarctic Ice Sheet, Antarctica1994Microwave, millimeter, neutrino, submillimeterSPT, AMANDA, IceCube, QUaD
Cerro Armazones ObservatoryCerro ArmazonesAtacama Desert, Chile1995Optical telescopeHexapod-Telescope
National Astronomical Observatory Sierra de San Pedro MártirBaja California, Mexico1967Optical telescope
Apache Point ObservatorySacramento PeakNew Mexico, United States1984Optical, solarSDSS, Dunn Solar Telescope
Cerro PachónCerro PachónAtacama Desert, Chile2000Optical, infraredGemini South, SOAR
National Astronomical Observatory Metropolitan Area of BogotáBogotá, Colombia1803Optical telescope
Paranal ObservatoryCerro ParanalAtacama Desert, Chile1999Optical, infraredVLT, VISTA
Fred Lawrence Whipple ObservatoryMount HopkinsArizona, United States1966Optical, gamma rayMMT, VERITAS
Roque de los Muchachos ObservatoryRoque de los MuchachosLa Palma, Canary Islands1979Optical, infrared, solar, gamma rayMAGIC, GTC, WHT, TNG, NOT, INT
Teide ObservatoryPico del TeideTenerife, Canary Islands1964Optical, solar, microwaveVTT, BRT, OGS, VSA
La Silla ObservatoryLa SillaAtacama Desert, Chile1969Optical telescopeNTT, ESO
Las Campanas ObservatoryCerro Las CampanasAtacama Desert, Chile1971Optical telescopeMagellan Telescopes, GMT
Lowell ObservatoryFlagstaffArizona, United States1894Optical telescope
Cerro Tololo Inter-American ObservatoryCerro TololoAtacama Desert, Chile1967Optical telescopeVictor M. Blanco Telescope
Calar Alto ObservatoryCalar AltoAlmería, Spain1975Optical telescope
Very Large ArrayPlains of San AgustinNew Mexico, United States1975Radio telescope
Kitt Peak National ObservatoryKitt PeakArizona, United States1960Optical, solar, radio telescopeMayall, WIYN, McMath-Pierce, VLBA
Special Astrophysical Observatory
of the Russian Academy of Science		Mount PastukhovCaucasus Mountains, Russia1966Optical telescopeBTA-6
Yunnan Astronomical Observatoryrural Kunming, Yunnan, Chinarural Kunming, Yunnan, China1972Optical telescope, Radio, Solar, InfraredLijiang 2.4m telescope, Fuxian Lake 1m solar tower, ynao 1m telescope, 10m radio telescope.
Mount Wilson ObservatoryMount WilsonCalifornia, United States1908Optical, solarHale Telescope, Hooker Telescope
Palomar ObservatoryPalomar MountainCalifornia, United States1936Optical telescopeHale Telescope, Samuel Oschin telescope