Petaluma's downtown is one of the best-preserved Victorian commercial districts in California, with block after block of ornate 1880s and 1890s brick buildings along Petaluma Boulevard and Kentucky Street. The area has been used as a film location so often — most famously for American Graffiti, which used Petaluma as a stand-in for 1960s Modesto — that you may feel a vague sense of recognition walking its blocks. It is a genuine working downtown with independent shops, good restaurants, and a farmers market on Saturday mornings.
The architecture is unusually consistent for an American small city: the Victorian commercial streetscape survived because Petaluma was essentially bypassed by the freeway era, its growth slowing enough that developers never had much incentive to tear down the old buildings. The result is a place that looks much as it did in 1895, with iron facades, elaborate cornices, and ground-floor storefronts that have housed one generation of merchants after another.