On the east edge of Petaluma stands the adobe at the center of General Vallejo's rancho.
The building
Mariano Guadalupe Vallejo ordered the adobe built in 1836, according to Wikipedia. It was the largest privately owned adobe built in California and is the largest example of Monterey Colonial architecture in the country. It served as headquarters for a working ranch and as a defense against possible attack by the Russians, then on the coast, or by Native tribes. It was originally two two-story buildings around an open courtyard. It became a California Historical Landmark in 1932 and a National Historic Landmark in 1970.
The rancho
State Parks calls it the largest private rancho in California between 1834 and 1846, at the center of one of the most prosperous private estates of the Mexican period.
Visiting
State Parks says the park is open daily from 10 a.m. to 5 p.m., and the adobe closes at 4:30 p.m. Admission is $3 for adults and $2 for youth, and free for children 5 and under. The park is at 3325 Adobe Road, off Highway 116, about 20 minutes from Sonoma. Dogs are allowed only in developed areas.