Chile is home to the most important observatories on earth. Well known examples are the ALMA Observatory in the Atacama Desert (the driest place on earth) in the north of Chile, and the Geminis, the southern hemisphere observatory located in the Elqui Valley in central-north Chile. The Northern Hemisphere
Chilean stargazing is widely considered the best in the world. The consistently high altitude, dry climate, and low levels of light pollution create the perfect cocktail for a clear night sky. Additionally, Chile is a special place for stargazing because it is one of the few places that offer reliably clear views of the night sky in the Southern Hemisphere observatory.
But these two Observatories are not alone. Due to the atmospheric conditions, there are almost 10 big observatories in throughout the north of Chile. You can find a full list of them here.
Many of the observatories run day tours for travelers and amateur astronomers, but do not run in the evening, and are primarily tours of the facilities. This is due to the high cost of the telescopes and its operation. Nevertheless, there are some excellent astronomy tours in both the Atacama desert and the Elqui Valley.