Biosphere 2 is one of the largest living laboratories in the world. It is an air tight greenhouse covering 3.15 acres and 7.2 million cubic feet of volume. This structure was originally created as an artificial environment like one on the planet Mars and to study the interaction of the Earth’s ecosystems. Inside Biosphere 2 is a rainforest, a million gallon salt water ocean, a coastal fog desert, and four other wilderness ecosystems. It has become non-profit education and research affiliate of Columbia University. And tours are welcome to view how this “replica” of Biosphere I (Earth) functions.