California note
Sonoma Plaza holds mission, Vallejo, and Bear Flag history
Sonoma Plaza was laid out in 1835, became a National Historic Landmark, and sits beside sites tied to Vallejo and the Bear Flag revolt.
Sonoma Plaza is one of those places where a lot of California history sits close together. General Mariano Vallejo laid out the eight-acre plaza in 1835, and it is the largest plaza of its kind in California.
The square also became a National Historic Landmark in 1961. City Hall sits in the middle, and its 1908 design has four matching sides. That way, merchants on any side of the Plaza could say City Hall faced them.
The heavier history is nearby, too. Sonoma Barracks was built in 1836 and later became headquarters for the Bear Flag Party. In June 1846, the Bear Flag was raised on Sonoma’s Plaza during the short-lived California Republic moment. Twenty-three days later, the United States took possession of California.
That is a lot for one walk. The Plaza is still a place for markets, events, playgrounds, and shade, but it also holds mission-era, Mexican-era, Bear Flag, and early statehood layers in a very small area.
Where to see it
Sonoma Plaza, Sonoma City Hall, Mission San Francisco Solano, and Sonoma Barracks.
Sources
Sources for this story
Reviewed July 2, 2026
Public sources for the places, events, and details above.
Connected places
Open the local directory
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