Three of California's oldest and best-preserved historic districts are in Petaluma. The Oakhill-Brewster Historic District, north and west of downtown, and the “A” Street Historic District, south and east of downtown, contain many carefully preserved 19th-century Victorian homes. The Petaluma Historic Commercial District, encompassing much of downtown, includes well-known landmarks like the Philip Sweed House (301 Keokuk St.), the United States Post Office (4th and D streets) and the Phoenix Theatre (201 Washington St.). Learn More...