Fodor's Expert Review Biosphere 2

In the town of Oracle, about 30 minutes northwest of Tucson, this unique, self-contained cluster of ecosystems opened in 1991 as a facility to test nature technology and human interaction with it. Now managed by the University of Arizona, the biomes include tropical rain forest, savanna, desert, thorn scrub, marsh, and ocean areas. The newest biome, the Landscape Evolutionary Observatory, tracks rainfall in simulated desert environments to study the effects of climate change on water sources and plant life in this region.

Guided walking tours take you inside the biomes, and a brief film gives an overview of Biosphere projects, from the original "human missions"—where scientists literally ate, slept, and breathed their work in a closed system—to current research. A snack bar overlooks the Santa Catalina Mountains.