Built to be completely sealed off from Biosphere 1 (that would be Earth), Biosphere 2 is a 3-acre campus of glass domes and pyramids containing five ecosystems: tropical ocean, mangrove wetlands, tropical rainforest, savannah and coastal fog desert. In 1991, eight biospherians were sealed inside for a two-year tour of duty from which they emerged thinner but in fair shape. Tours take in the biospherians' apartments, farm area and kitchen, the one-million gallon 'tropical ocean' and the 'technosphere' that made it all possible.
Although this experiment was ostensibly a prototype for self-sustaining space colonies, the privately funded endeavor was engulfed in controversy. Heavy criticism came after the dome leaked gases and was opened to allow a biospherian to emerge for medical treatment. After several changes in ownership, the sci-fi-esque site is now a University of Arizona-run earth science research institute.
Biosphere 2 is near Oracle, about 30 miles north of Tucson via Hwy 77 (Oracle Rd) or 30 miles east of the I-10 (exit 240, east on Tangerine Rd, then north on Hwy 77). No pets.
