Onyx Cave (Arizona)

Cave of the Bells is located in Sawmill Canyon on the eastern slopes of the Santa Rita Mountains of Santa Cruz County, Arizona. The cave contains a lake which is 80 meters below the entrance level. The lake has been measured at 76 °F (24 °C) and is believed to be warmed by sources below. Nearby Onyx Cave is also of interest.

Kentucky Camp is a ghost town and former mining camp along the Arizona Trail in Pima County, Arizona, United States, near the community of Sonoita. The Kentucky Camp Historic District is listed on the National Register of Historic Places and has been since 1995. As it is located within Coronado National Forest, the United States Forest Service is responsible for the upkeep of the remaining buildings within the Kentucky Camp Historic District.

Greaterville is a populated place situated in Pima County, Arizona, United States. It has an estimated elevation of 5,203 feet (1,586 m) above sea level.

Fort Buchanan was a US Army post founded in 1856 three miles southwest of present-day Sonoita in Santa Cruz County, Arizona, on the east slope of what is now called Hog Canyon. At the time, the area was under constant threat from hostile Apaches. Full-scale war with the local Chiricahua Apache was initiated by the Bascom affair in early 1861, during which Lieutenant George Nicholas Bascom and his patrol were based at Fort Buchanan. The post was officially abandoned in 1861, though troops of the California Column occasionally manned the post during the American Civil War. In February 1865, Apaches attacked and burned the fort in the Battle of Fort Buchanan, forcing the small garrison to retreat. It was then abandoned for good, and Fort Crittenden was established half a mile east on the flats in 1867.After having been lost for years, the ruins of the fort were rediscovered in 1929 by Harry J. Karns, mayor of Nogales, Arizona, and Arizona Superior Court Judge W. A. O'Connor.

The Battle of Fort Buchanan was an Apache attack on the United States Army post of Old Fort Buchanan in southern Arizona Territory, which occurred on February 17, 1865. Though a skirmish, it ended with a significant Apache victory when they forced the small garrison of California Volunteers to retreat to the Santa Rita Mountains. Fort Buchanan was the only American military post conquered during the war against the Chiricahua.

Fort Crittenden, originally Camp Crittenden, was a United States Army post built in 1867 three miles from Sonoita, Arizona along Sonoita Creek. It was established for campaigning against the Apache and to protect American pioneers in the area.

The Santa Rita Abbey is a monastic community of the Trappistine branch of Cistercian nuns located in Sonoita, Arizona, within the Diocese of Tucson.

The Fred Lawrence Whipple Observatory is an American astronomical observatory owned and operated by the Smithsonian Astrophysical Observatory (SAO); it is their largest field installation outside of their main site in Cambridge, Massachusetts. It is located near Amado, Arizona on the summit, a ridge and at the foot of Mount Hopkins. Research activities include imaging and spectroscopy of extragalactic, stellar, solar system and extra-solar bodies, as well as gamma-ray and cosmic-ray astronomy.

The Infrared Optical Telescope Array (IOTA) was a stellar interferometer array. IOTA began with an agreement in 1988 among five Institutions, the Smithsonian Astrophysical Observatory, Harvard University, the University of Massachusetts Amherst, the University of Wyoming, and MIT/Lincoln Laboratory, to build a two-telescope stellar interferometer for the purpose of making fundamental astrophysical observations, and also as a prototype instrument on which they could perfect techniques which could later lead to the development of a larger, more powerful array. On site construction went on for all 1993 and 1994, with first fringes in December 1993. It is located at Fred Lawrence Whipple Observatory. In 2000 the third telescope came online providing closure phase observations, allowing aperture synthesis imaging to be performed for the first time at IOTA. The array was decommissioned and disassembled in summer 2006 due to lack of funding.

The MMT Observatory (MMTO) is an astronomical observatory on the site of Fred Lawrence Whipple Observatory (IAU observatory code 696). The Whipple observatory complex is located on Mount Hopkins, Arizona, US (55 km south of Tucson) in the Santa Rita Mountains. The observatory is operated by the University of Arizona and the Smithsonian Institution, and has a visitor center in nearby Amado, Arizona. The MMTO is the home of the MMT (formerly Multiple Mirror Telescope), which has a primary mirror 6.5 m in diameter. The name comes from the six smaller mirrors originally used before the single primary mirror was installed in 1998. The primary mirror has a special lightweight honeycomb design made by the University of Arizona's Steward Observatory Mirror Laboratory. The MMT is housed in a building which allows the walls and roof around the telescope to be completely rolled back, allowing it to cool down very quickly in order to improve observation.

Mount Hopkins is a 8,553-foot (2,607 m) peak of the Santa Rita Mountains range, in Santa Cruz County, southern Arizona. The peak was named after Gilbert Hopkins, who was killed nearby during the Battle of Fort Buchanan in 1865. It is in the Coronado National Forest and is bounded on three sides by the Mount Wrightson Wilderness.

The MINiature Exoplanet Radial Velocity Array (MINERVA) is a ground-based robotic dedicated exoplanet observatory. The facility is an array of small-aperture robotic telescopes outfitted for both photometry and high-resolution Doppler spectroscopy located at the U.S. Fred Lawrence Whipple Observatory at Mt. Hopkins, Arizona. The project's principal investigator is the American astronomer Jason Eastman. The telescopes were manufactured by PlaneWave Instruments.