Sonoma Plaza is the largest town square in California — eight acres of park, fountain, duck pond, and lawn at the centre of the city. The plaza was laid out in 1835 by General Mariano Vallejo on the Spanish colonial model, and the surrounding buildings include some of the most significant historic structures in California. The farmers' market on Tuesday and Friday mornings is one of the best in Sonoma County, with wine country produce from the surrounding farms.
The Bear Flag Monument at the northeast corner of the plaza marks the spot where the California Republic was declared in 1846. The surrounding ring of restaurants and shops is well-stocked for a town of this size, reflecting the wine-tourist economy that has made Sonoma prosperous without entirely homogenising it. The plaza is pleasant at any time of day; early morning before the tourists arrive is particularly good.