If you tire of getting herded around in the large observatories, you may like these small, personalized astronomical tours (in English or Spanish). Held in the on-site amphitheater, tours start with a short video exploring the basics of astronomy, followed by a listen to interstellar sounds via radio telescopes; you'll then get up close with the celestial bodies via scientific-grade telescopes.
It's largely an open-air event – after the introduction the whole thing takes place under the star-filled sky and small group sizes mean plenty of telescope time for everybody – but it can get frosty. Dress warmly (although the blankets, wine and vegetable soup that come with the tour help cut the chill). Reserve ahead; free transportation is included.