Santiago's national astronomical observatory sits within the Cerro Santa Lucía park, its white dome visible above the trees from the Alameda. The building dates from 1862 and the observatory from 1852 — it is one of the oldest observatories in South America still in use. The central location means that serious research has long since moved to the dark skies of the Atacama, but the historical instrument collection and the night-observation programmes for the public give it genuine value.
The observatory organises public observation evenings on Fridays and Saturdays when skies are clear. The viewings use modern telescopes and are guided by university astronomers; book ahead as spots are limited. The building and its hilltop location within the park are also worth seeing during the day as part of a Cerro Santa Lucía visit.