SPACE has been putting people in front of telescopes in San Pedro since 2003, roughly a decade before anyone else in town thought of selling the night sky. More than a hundred thousand people have taken the tour. It is the one astronomy operation here that is an observatory first and an agency second.
The telescopes are the reason to choose them. Most San Pedro "astronomical towers" put you behind 30 or 40 cm of aperture; SPACE uses 60 cm and 72 cm instruments and a 1.15 m, which they say is the largest telescope in the southern hemisphere open to the public. Groups are capped at sixteen. The tour runs two to three hours, in French, English or Spanish, finishing with a hot drink and a photograph under the stars. It costs 45,000 pesos.
Two warnings from their own site, and they are worth repeating. There are no tours for the seven nights around full moon. And they work with no other agency in San Pedro — if an agency tells you it is sending you to SPACE, it is sending you somewhere else.
Book by the form on their website. They have no telephone, no WhatsApp, and no shopfront; tours are commonly full weeks ahead, and they turn away ten to twenty people a night.