The former library, built in 1904, is now home to the Petaluma Historical Museum. A unique feature of the building itself is that it has the largest free-standing leaded glass dome in Northern California. The museum contains exhibits representing the egg and dairy industries, the riverside history of Petaluma and its residents, and a Miwok Indian exhibit to name a few. An historical research library is also available at the museum. For more information, please visit the official web site.