Top ChoiceLandmark in Mauna Kea

Mauna Kea's Summit Area

At 13,796ft in the air, you are above 40% of the atmosphere and 90% of its water vapor – apparently perfect conditions for growing the giant mushroom-like observatories that have popped up around the summit....

Top ChoiceArchaeological Site in Mauna Kea

Lake Waiʻau

On an island with a conspicuous dearth of surface water, tiny Lake Waiʻau's existence on a porous lava mountain is something of an enigma. Hawaiian legends say it's bottomless, connecting the realm of the heavens...

Historic Site in Mauna Kea

Mauna Kea Adz Quarry

Quarries scattered over 7.5 sq miles produced tons of exceptionally dense and fine-grained basalt (dubbed Hawaiʻiite) used to make a tool similar to an ax called an adz. The scale of the operation is difficult to...

Observatory in Mauna Kea

Subaru Telescope

When it came online in 1999, Japan's 26.9ft Subaru Telescope was the most expensive observatory ever constructed. The 22-ton mirror is one of the largest optical mirrors in existence. The telescope helped create...

Observatory in Mauna Kea

WM Keck Observatory

Mirrors larger than 26.2ft are so heavy that gravity distorts them as they move. Keck's breakthrough design overcame that limitation in 1993 by using a series of 36 hexagonal mirror segments mounted and...

Observatory in Mauna Kea

Thirty Meter Telescope (planned)

Walk behind the Keck Twins and look northwest and you'll see...nothing. Down there is the ideal location for the TMT, which supersizes Keck's many-small-mirrors design to create the world's most advanced and...

Observatory in Mauna Kea

Submillimeter Array

These eight 19.7ft radio telescopes work together (via supercomputer) to create image resolutions equal to an antenna 0.3 miles in diameter. The SMA detects millimeter and submillimeter radiation, allowing...

Observatory in Mauna Kea

United Kingdom Infrared Telescope

Even though this 3.8m (12.5ft) telescope is the second-largest dedicated infrared telescope in the world, it will soon be decommissioned according to the new summit management plan for growth. Among its...

Mountain in Mauna Kea

Puʻu Wekiu

Hawaiian cultural practitioners ask that visitors respect the sacred true summit of Mauna Kea and not hike the trail to the top of the cinder cone (13,796ft). It's opposite the UH 2.2m Telescope where there is...

Observatory in Mauna Kea

University of Hawai‘i 0.9m Telescope

Hoku Kea was meant to be a teaching telescope, but the original 0.9m (3ft) mirror was delivered warped and the manufacturer went bankrupt. So, it has mostly been inactive for the last six years, making it an easy...

Observatory in Mauna Kea

Gemini Northern Telescope

When this 26.6ft telescope is paired with its twin in Chile, they are able to cover almost the entire sky. In 2014, Gemini used speckle imaging to help confirm the existence of Kepler 186f, the first known...

Observatory in Mauna Kea

NASA Infrared Telescope Facility

Able to utilize multiple sensors, this 3m (9.8ft) infrared telescope has diverse applications, from close-to-home observations – like measuring the ozone on Mars, sleuthing out meteor impacts on Jupiter, or...

Observatory in Mauna Kea

University of Hawaiʻi 2.2m Telescope

UH2.2 (if you go metric, UH88 if you prefer inches) was a pioneer of Mauna Kea. As the first large telescope on the mountain (1970), its great imagery convinced the world that the roof of Hawaiʻi was the best...

Observatory in Mauna Kea

Very Long Baseline Array

One of 10 identical radio receivers that span 5351 miles from Mauna Kea to St Croix, US Virgin Islands. The $85 million project went online in 1993 and has tackled some massive projects equal to its size,...

Observatory in Mauna Kea

Canada-France-Hawaii Telescope

This 3.6m (11.8ft) optical/infrared telescope's first light was 1979, making it the oldest operational telescope on the mountain. It specializes in wide-field imaging, examining large structures like remote...

Historic Site in Mauna Kea

Apollo Valley

Just past Mile 4 on the east side of the summit road, a washed-out valley full of grayish glacial till and rocks is a dead ringer for the surface of the moon. So much so that the Apollo astronauts trained here...

Historic Site in Mauna Kea

Humu‘ula Sheep Station

For 100 years these pastures were filled with sheep, and that historical legacy is marked by nearby rock walls stacked by Japanese laborers and the Humu‘ula Sheep Station at the corner of Saddle and Mauna Kea...

Observatory in Mauna Kea

James Clerk Maxwell Telescope

You can easily recognize the JCMT by the world's largest sheet of Gore-Tex® which covers the telescope allowing it to operate night and day. Its 49.2ft mirror captures submillimeter wavelengths, and specialized...