Arcosanti is an experimental city in Arizona and is the brainchild of Paolo Soleri. It uses his concept of 'arcology' which is the melding of architecture and ecology to design an urban environment where the architecture makes the best use of the ecology and has the minimum impact on the environment and makes the best use of natural resources. The city, when completed, is designed to house 5000 people and include commercial, residential, retail and cultural spaces using only 15 acres of land.