How to visit Astronomy Sites

ESO operates observatories at three sites in Chile: Chajnantor, Cerro Paranal and Cerro La Silla (“Cerro” is the Spanish word for “Mountain”).

The guided tours are free of charge, but registration is required as there is limited space. Large groups are asked to register as far in advance as possible.

For special inquiries about the visit or information which is not available on our web pages, please contact: For emergency calls about the visit or booking:+56 – 9 – 98395312.

Cerro Paranal

Tourist and student visits to Paranal Observatory are scheduled every Saturday at 10:00 or 14:00. A dedicated web page with all relevant information about Weekend Visits to Paranal is available.

To register for a visit to Paranal, please submit the Visitor Form. We do not accept bookings by mail or phone.

La Silla

La Silla Observatory is open for public visits every Saturday at 14:00, except in July and August. Please check the Weekend Visits to La Silla page for further details.

To register for a visit to La Silla, please submit the Visitor Form. We do not accept bookings by mail or phone.

Tourist and student visits to the ALMA Operations Support Facility (OSF) are scheduled every Saturday and Sunday from 9:00 to 13:00. A dedicated website with all the relevant information about weekend visits toALMA is available. For tickets and information please go here. Prior registration is necessary. For safety reasons, operations on the Chajnantor Plateau (the Array Operations Site, or AOS, where the antennas are located) are not open to visitors.

To register for a visit to the ALMA Operations Support Facility, please go to the following link.

We make every effort to accommodate teacher/student groups and professionals involved in activities related to astronomical research/engineering. The following should be considered before making a tour request:

Anyone with pre-existing health issues that might be exacerbated by extreme altitude should not plan to visit Gemini South without a doctor’s evaluation (Gemini South is located at an altitude of about 2700 meters above see level).

The guided tours are free of charge, but registration is required as there is limited space. The tours are scheduled on Friday morning.

Due to technical reasons it is not possible to visit the observatory between May 31 and September 1.

All tour participants must sign and return (email prefered or fax) GS Visitor Safety Information (English | Spanish) and read the Gemini Safety Guidelines (English | Spanish) prior to departing sea-level for any visit to the Gemini telescope facilities;

Gemini cannot offer transportation – appropriate transportation is the responsibility of the visitor.

For reservations and further information about the visits please contact:

Cerro Tololo is open to the public every Saturday, summer and winter, weather permitting. For safety and security reasons, the number of visitors is limited to two groups of 40 people. One group meets at the gatehouse at 9 am and the other at 1pm. Because the number of visitors is limited, advance reservations are essential. During the tourist season from mid-December to March, reservations must be made several weeks in advance. To make reservations, call 51 2205 200. Permits must be picked up in La Serena before proceeding to the mountain. Access to the mountain is by private vehicles only. There is no public transportation.

Permits are free and may be obtained from the Reception Desk in La Serena. Tours are conducted at no charge by a professional guide. Total elapsed time from leaving the gatehouse until returning to the highway is approximately three hours.

For more information on public access to CTIO, click here.