The Atacama Large Millimeter/sub-millimeter Array (ALMA) is an astronomical interferometer of radio telescopes in the Atacama desert of northern Chile. Since a high and dry site is crucial to millimeter wavelength operations, the array has been constructed on the Chajnantor plateau at 5,000 metres altitude, near Llano de Chajnantor Observatory and Atacama Pathfinder Experiment. Consisting of 66 12 metres (39 ft), and 7 metres (23 ft) diameter radio telescopes observing at millimeter and sub-millimeter wavelengths, ALMA is expected to provide insight on star birth during the early universe and detailed imaging of local star and planet formation.