Located about 30 miles north of Tucson, the Biosphere 2 is one of Southern Arizona's most breathtaking attractions. The term "Biosphere" was derived by its founders from the idea that it is modeled after planet Earth—the first biosphere.
Standing at 91 feet at its highest point, the Biosphere 2 is sealed from the earth by a 500-ton steel liner. It was originally built by Edward P. Bass and his Space Biospheres Ventures. During two separate missions in 1991 and 1994, teams were sealed inside of the Biosphere 2 as part of a grand experiment. The facility is now operated by the University of Arizona.
One of best ways to experience Biosphere 2 is the guided tour, which illustrates the importance of these various ecosystems. The biosphere is open every day, except Thanksgiving and Christmas Day, from 9 a.m. to 4 p.m.