Petaluma's main draws are its historic downtown and the surrounding landscape. The preserved Victorian commercial district makes for good wandering, and the Adobe State Historic Park is one of the more underrated historic sites in the North Bay. The Shollenberger Park wetland reserve at the edge of town is good for birdwatching, and the Petaluma River waterfront has been converted from a working port to a pleasant mix of restaurants, galleries, and walking paths.
Rancho Obi-Wan, north of town, holds the Guinness World Record for the world's largest privately held Star Wars memorabilia collection — an unlikely but genuinely spectacular attraction that requires advance booking. The Saturday farmers market in downtown is worth timing a visit around.