The Observatory operates the "Jorge Sahade" telescope, a 2.1 m Boller & Chivens reflector with Ritchey-Chretien optics. It is located at San Juan province in the Western part of Argentina at the southern latitude of -31° 47'. The site is remote (220 Km from the administrative offices in the city of San Juan), but the sky is not polluted by lights or other factors. A state law has been passed by the state congress to protect the site and its sky as an astronomical reservation. Recently the site has been included among the National Parks and Reservations, which guarantees a full protection.

The number of useful nights per year is around 300. At the top of the mountain there are mechanical and electronic shops along with lodging facilities for the technical staff and visiting astronomers. A commercial line provides electrical power but the observatory has its own power plant. Other services are available at the mountain including water supply, communications, internet, computing facilities and a library. The auxiliary instrumentation at present is the following:

• A Boller & Chivens cassegrain spectrograph, which has six gratings which provide dispersions between 30 and 250 A/mm. The spectrograph is currently used with a Photometrics CCD of 512 x 512 pixels.

• A REOSC Cassegrain echelle used with a TEK CCD 1024x1024 pixels, through an agreement with the University of Columbia. The dispersion is 0.14 A/pix.

• A direct module and camera with a focal reducer. The same TEK chip is used for direct imaging.

• A photopolarimeter for observing UBVRI simultaneously, completely automatic. This is available through an agreement with the Torino Astronomical Observatory in Italy.

• A new photopolarimeter completely automatic with two channels has been recently finished at the technical shop at CASLEO. It is presently in operation.

• A fiber fed optical bench echelle spectrograph has been recently commissioned. It provides spectra in the blue-red region with a maximum resolving power of 40,000

Also is in operation an experiment for the detection of gamma rays. The experiment consists of three telescopes, which detect gamma rays through Cherenkov radiation. This experiment is part of an agreement with the Fred Wipple Observatory of the Smithsonian Institution.

Since 2000 is operating a submillimeter radiotelescope for observations of high-energy phenomena in the Sun. The radiotelescope is the result of a joined project between the CRAAM-FAPESP from Brasil, the CFA from Switzerland and CASLEO-IAFE-CONICET from Argentina. The SST has a 1.5m diameter and operates in 405Ghz and 212Ghz. The equipment includes facilities to study the propagation properties of the atmosphere at the site at such frequencies. Recently through an agreement with Observatorio do Valongo, Brasil,  we have added a Celostat and a bench spectrograph for observing Hydrogen lines in the spectrum of the Sun at a rate of several per minute.

The users of CASLEO are scientists from the national universities that participate in the agreement and also from other research units from Argentina and from abroad. The distribution of the users by country during 2000, can be seen in the figure.

A new telescope of 60 cm from the University of Toronto, Canada, is under installation at the top of Cerro Burek that has been developed to permit the installation of other instruments. The new telescope will operate at the beginning of 2003.

The observatory is opened to collaborations with other institutions to increase the observing capabilities, installing new telescopes and other kinds of instrumentation at the site.

At the 400,000-habitant city of San Juan, the capital of the Province, the observatory has its administrative offices and some space for developing and designing new instrumentation. Also the facilities of the nearby University of San Juan may be used.