If you came here because you were told the valley offers the most stunning views of the night sky, you will be disappointed. Nowadays, the city produces so much light pollution, you will have a hard time finding a spot that is really dark. Even deeper into the Pisco valley, it will be hard to keep up the darkness due to the ever increasing flow of tourists into this region. However, do not be disappointed and kill your sadness with a fine Pisco (coke, sour or pure).
It provides tours in Spanish and English. Tours are in the evening and include star observation using big telescope, outside constellation description using laser pointer, taking pictures of the moon and short theoretical PowerPoint. Tours can be booked on the same day at the office: Gabriela Mistral 260. Instead of taking a minibus, you can also hike there and potentially see the night sky after dusk.
Check out this scenic dam between La Serena and Vicuña.
Climb the small mountain (the one with the antennas on) just north of town for a complete panorama of the surroundings. Mind the sun, and bring some water along.