On Saturday, readers of Smithsonian Magazine and Smithsonian.com are being offered free entry into museums across the country in a promotion called Museum Day.

Participating Bay Area institutions include the Exploratorium and California Academy of Sciences in San Francisco; UC Berkeley Art Museum and Pacific Film Archive; the Chabot Space and Science Center in Oakland; the Lindsay Wildlife Museum in Walnut Creek; and the Niles Essaney Silent Film Museum in Fremont.

Museum Day is open to all Smithsonian readers and friends. Participants must present the Museum Day Admission Card available in the September 2007 issue of Smithsonian Magazine, or download one at www.smithsonianmagazine.com/museumday/articles/card.php.

The card, which grants admission to two people, is for use on Saturday only; it does not cover special exhibits or IMAX screenings.