ALMA is open every Saturday and Sunday morning to members of the public who want to visit its facilities located in northern Chile (50 km from San Pedro de Atacama). Visitors must register in advance by completing and submitting the form below. Only those who are registered in advance may visit the ALMA Operations Support Facility (OSF), where ALMA personnel work and where visitors can observe the control room, laboratories and usually antennas under maintenance and the antenna transporter. For safety reasons, operations on the Chajnantor Plateau (the Array Operations Site, or AOS, where the antennas are located) are not open to visitors, due to the location at 5,000 meters above sea level.
To obtain an entry pass (free of charge), look for the date you plan to visit. If there are no available spots, you can register for the wait list. Based on the previous visits, we know that not everyone who registers actually shows up. Therefore, if you are on the waiting list, we recommend that you come at 8:30 am to the bus departure location in San Pedro de Atacama on the day you chose to see if any space is available on the bus.
Each person, including minors, must register individually. ALMA does not allow visits from children under 4 years old. Spaces reserved for children cannot be used by adults. The requested information must be provided in its entirety, especially the contact information to be used in the event of a change or cancellation due to weather, problems with the roads or emergencies.
On the day of the visit, an ALMA bus will leave at 9:00 am from Tumisa Street, close to the corner of Pedro de Valdivia Ave. (see the red spot on the map). This is close to the entrance to the artisan fair called “Pueblo de los Artesanos” and near the San Pedro de Atacama bus terminal.
Please remember to bring your ID with you.
If you miss the bus, you may NOT travel in another vehicle to ALMA, because your spot will be taken by those on the waiting list.
The bus will return to the same location around 1:00 pm.
Q: Why does a ‘closed’ message appear on the registration page?
A: Because there are no more spaces available for that day.
Q: When will I be notified if spaces are available for those on the waiting list?
A: Considering that we do not have the capacity to confirm if spaces are available and considering that not everyone who registers actually shows up, if you are on the waiting list, we recommend that you come to the bus departure location at 8:30 am on the day you chose to see if any space is available on the bus.
Q: When is it possible to visit ALMA?
A: Opportunities for the public to visit the observatory will be available throughout the year on Saturday and Sunday mornings, weather permitting.
Q: Are there days reserved for only adults and others for children?
A: No. There are 3 types of tickets available for each tour: Adults (age 9 and older), Children (4-8 years) and wait list (4 years and older). There is limited capacity on the visits for children between 4 and 8 years old due to the number of child seats available in the bus, which are required for safety reasons. Children must always be accompanied by an adult.
Q: Can I transfer my ticket to someone else?
A: Registration is assigned individually and non transferable.
Q: I obtained a ticket, but there is an error in my contact information and I haven’t received the tickets by email. How can I recover it?
A: You can recover tickets directly at welcu.com with your user name and password. If there are errors in your contact information, write to us at and we will correct them.
Q: Is it possible to register for group visits?
A: Yes. The system allows you to request a maximum of four adult and two child tickets for each day. However, you must enter the information (name and ID or passport number) for each member of the group.
Q: Can I participate if I have a special need?
A: Yes. If you have a special need and/or disability, you can use your own vehicle to travel to ALMA, but prior to your trip, please send the license plate and driver details to firstname.lastname@example.org .Additional vehicles will enter the observatory in caravan behind the ALMA bus.