Petaluma, a historic riverfront city in Sonoma County, offers a variety of free activities:

1. Petaluma Historical Library and Museum: Explore local history in a beautiful Carnegie Library building.
2. Helen Putnam Regional Park: Hike or bike through oak-studded hills with panoramic views.
3. Shollenberger Park: Enjoy bird watching and walking trails in this wetland area.
4. Petaluma Arts Center: View rotating art exhibits (free admission on the first Thursday of each month).
5. Petaluma Adobe State Historic Park: Visit this 19th-century ranch house (exterior viewing is free).
6. Petaluma River Park: Stroll along the river and enjoy public art installations.
7. Farmers’ Markets: Visit the East Side or Downtown markets for local produce and crafts.
8. Walnut Park: Enjoy concerts in the park during summer months.