The observatory, in order to bring the world closer to Radio astronomy, has designed a free of charge visitor program to the Operation Support Facility (OSF). At 2.900 m.a.s.l in the Atacama Desert, the OSF is where the ALMA staff works, here is the control room of the antennas, labs, some antennas under maintenance and, normally, at least one antenna transporter. Chajnantor at 5.000 m.a.s.l is not available for visitors for safety precautions.

Nowadays, the categories for visits that are enabled: educational or scientific, science outreach media, and friends and family from ALMA staff. All these must be requested one month in advance and must be approved by the Director of ALMA, Dr. Sean Dougherty.