The Pereira Octagon Barn of San Luis Obispo is a historically and culturally important structure on the Central Coast of California. It was built in 1906 by Henri LaFranchi, John Damaso, and a third, unknown man. Since there were no other octagonal barns in the area, the builders may have worked from patterns of octagonal construction in farm journals or catalogs.
The first user of the barn was Italian-Swiss immigrant Antonio Stornetta, who leased the barn for his Santa Fe Dairy operation until 1917. Joaquin and Josephine Pereira, with Josephine's sister Eleanor and Eleanor's husband Manuel Garcia, purchased the property in 1920 and made it part of an adjoining dairy operation in the Los Osos Valley. They were typical of many first- and second-generation Portuguese Americans, who followed in the footsteps of the Italian-Swiss in the dairy business.
Wikipedia https://en.wikipedia.org/wiki/San_Luis_Obispo_Octagon_Barn
Coordinates 35°14'12.735" N -120°40'46.354" E