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Kitt Peak National Observatory
Homepage of Kitt Peak National Observatory (KPNO) which is the one of the premier astronomical observatory used by professional astronomers in the United States. Although the site is mostly geared toward the professional, the Kitt Peak...
Curated OER
Wikipedia: National Historic Landmarks in Vermont: Stellafane Observatory
Contains original clubhouse of the Springfield Telescope Makers, Inc. (1924), and the first large optical telescope (1930) built and owned by that kind of amateur society.