Lowell Observatory is an astronomical observatory in Flagstaff, Arizona, United States. Lowell Observatory was established in 1894, placing it among the oldest observatories in the United States, and was designated a National Historic Landmark in 1965. In 2011, the Observatory was named one of "The World's 100 Most Important Places" by Time Magazine. It was at the Lowell Observatory that the ninth planet Pluto was discovered in 1930 by Clyde Tombaugh.
The Clark Telescope Dome on Mars Hill
The Slipher Rotunda Museum at Lowell Observatory
Percival Lowell in the observer's chair of the Alvan Clark 61 cm (24-inch) refractor
Historic Clark telescope installed in 1896 and housed in a wooden dome resting on automobile tires.
An observatory is a location used for observing terrestrial, marine, or celestial events. Astronomy, climatology/meteorology, geophysics, oceanography and volcanology are examples of disciplines for which observatories have been constructed. Historically, observatories were as simple as containing an astronomical sextant or Stonehenge.
The Sphinx Observatory on a mountain top in the Swiss Alps at 3,571 m (11,716 ft)
Atacama Large Millimeter Array, Chile, at 5,058 m (16,594 ft)
Paranal Observatory, Chile, home of the VLT at 2,635 m (8,645 ft)
The Mauna Kea Observatories, Hawaii, home of several of the world's largest optical telescopes at 4,205 m (13,796 ft)