Where is Lowell Observatory, the place where Clyde Tombaugh discovered Pluto in 1930, located?

Lowell Observatory is an astronomical observatory in the U.S. in Flagstaff, Arizona. It was was established in 1894. Thus, it is one of the the oldest observatories in the United States. In 1965, it was designated a National Historic Landmark.

In 2011, the Lowell Observatory was named one of "The World's 100 Most Important Places" by Time Magazine. It was specifically at the Lowell Observatory that the dwarf planet Pluto was discovered by Clyde Tombaugh in 1930.

Currently, the observatory operates several telescopes at three locations in the Flagstaff area. The main facility is located on Mars Hill just west of downtown Flagstaff, and it houses the original 61-centimeter (24-inch) Clark Refracting Telescope, although its role today is as a public education tool and not research.