Biosphere 2, self-sustaining ecosystem, cactus in front of facility with tropical rainforest, Oracle, Arizona, USA, North America

american americas america architecture arizona attractions attraction biosphere 2 building complexes building complex cacti cactus family cactus contemporary ecological system ecological ecology ecosystems ecosystem environmental environment exterior views exterior view facilities facility famous place forests forest glasses glass independance it company modern architecture nature nobody no one no people north america oracle out place of interest plants plant prickly projects project pyramid shaped pyramidal pyramid shapes pyramid shape rain forests rain forest rainforest sciences science scientific research scientific sights sight spiky spiny tourist attractions tourist attraction trees tree tropical tropics unique united states of america united states us american usa us wilderness wood