General Mariano Guadelupe Vallejo founded the pueblo of Sonoma in 1836 and built his home and the Mexican Army Barracks and Servents Quarters right on the present day square. Across the street from the barracks is the Mission San Francisco Solano de Sonoma founded in 1823 by Padre Jose Altamira. It is the northern most and the last, number 21, mission in California built by the Franciscan Order of monks and local Native Americans.
You get a lesson on California history in one spot. There are furnished buildings to tour - from the Catholic mission, to the soldiers barracks to General Vallejo's home. 35 American settlers arrested General Vallejo in June 1846 and raised Califonia's bear flag. But the Republic of California only lasted a few days. It was quite interesting to learn the histry and see how life was 150 years ago.
This state park preserves the mission, the military barracks and a collection of historic buildings in Sonoma.