5.4 miles away
Acadia Ranch Museum
A historic Oracle ranch complex built 1885-1930, listed on the National Register in 1984 and run as a museum by the Oracle Historical Society.
Biosphere 2
The largest closed ecological system ever created, built by 1991 and now a University of Arizona research facility.
- Rank in Arizona
- #24of 727 ranked
- Overall score
- Score 63.2 out of 100medium confidence
- Category
- Landmark
Biosphere 2 is an Earth system science research facility in Oracle, operated by the University of Arizona. The structure covers 3.14 acres and was built between 1987 and 1991 as a materially closed ecological system, or vivarium; it remains the largest ever created. It was designed to test whether a closed ecological system could support and maintain human life away from Earth, standing in for the planet's own biosphere, and to study the web of interactions within life systems across areas modelled on different biomes. Alongside those biomes and living quarters for its occupants, the facility held an agricultural area and work space for studying the relationships between people, farming and technology. Its stated mission today is research, outreach, teaching and public education about Earth and its living systems.
Where it is
Biosphere 2 is a landmark near Oracle, in Pinal County. It is one of the landmarks in this database, and appears in the statewide ranking of Arizona attractions.
How this ranking was reached
No official visitor count is published for Biosphere 2, so its score rests on public interest and tourism significance, and is capped below the level a measured attraction can reach. That is why the medium confidence above is not higher. The weighting is explained in full on the methodology page, and every axis is broken out under Facts and sources at the foot of this page.
Note on the data: No official visitor count is published for this attraction.
Sources
- Public interest: Wikimedia pageviews (en.wikipedia, human traffic), 2024
- Coordinates and designations: Wikivoyage(opens in a new tab)
- County: U.S. Census geography via FCC Area API, resolved from coordinates
- Official site: http://www.b2science.org/(opens in a new tab)
Record last verified 2026-08-12.
More photographs
Daniel Oberhaus, CC BY-SA 4.0 · licence(opens in a new tab) · source(opens in a new tab) 
CGP Grey, CC BY 2.0 · licence(opens in a new tab) · source(opens in a new tab)
Nearby attractions
9.2 miles away
Peppersauce Cave
A limestone cave with about a mile of mapped passages in the Santa Catalina Mountains south of Oracle, visited by some 23,000 people a year.
9.9 miles away
Mount Lemmon Ski Valley
The southernmost ski area in the continental United States, on Mount Lemmon north of Tucson at 9,157 feet.
10 miles away
Santa Catalina Mountains
The range north of Tucson, rising to 9,157 feet at Mount Lemmon and climbed by the 27-mile Catalina Highway.
10 miles away
Mount Lemmon Observatory
A University of Arizona observatory on Mount Lemmon, 28 kilometres north-east of Tucson in the Coronado National Forest.
10 miles away
Catalina State Park
Foothills and canyons at the base of the Santa Catalina Mountains north of Tucson, holding nearly 5,000 saguaros.
Facts and sources
Place
- Category
- Landmark
- Destination
- Oracle
- County
- Pinal County
- State
- Arizona
Visitation
- Annual visits
- Not published
Ranking
- Overall score
- 63.2 / 100
- Visitation score
- No published count
- Popularity score
- 85.0
- Significance score
- 45.0
- Confidence
- medium
Visiting
- Official website
- b2science.org(opens in a new tab)
- Coordinates
- 32.5788, -110.8506
- Last verified
- 2026-08-12