Biosphere 2 is the largest man-made, self-sustaining ecosystem ever built. You will experience this engineering marvel firsthand through a trail system which travels along a variety of ecosystems, including a 40-foot ocean cliff where you can look down into the million-gallon tropical ocean. Where scientists were once sealed into the Biosphere, guests can now go under the glass themselves and learn about the ongoing research and education led by the University of Arizona.
Address: 32540 S. Biosphere Rd., Oracle, AZ (28.6 miles away)
Phone: (520) 838-6200