Steward Observatory is the research arm of the Department of Astronomy at the University of Arizona (UA). Its offices is located on the UA campus in Tucson, Arizona (USA). Established in 1916, the first telescope and building were formally dedicated on April 23, 1923. It now operates, or is a partner in telescopes at five mountain-top locations in Arizona, one in New Mexico, and one in Chile. It has provided instruments for three different space telescopes and numerous terrestrial ones.