NO. 179 CASTRO-BREEN ADOBE - Also known as "Castro House," the adobe is associated with Jose Castro, Commandant General of Northern California. Castro built the house, which faces the plaza, for his administrative use and for residential use by his secretary. In 1848, the house was purchased with California gold by the Breens, a prominent pioneer family famous as survivors of the ill-fated Donner party of 1846. The Breen family lived in the Castro-Breen adobe for many years. 
Location: San Juan Bautista State Historic Park, 2nd and Washington Sts, San Juan Bautista
Listed on the National Register of Historic Places: NPS-70000141

NO. 180 PLAZA HOTEL - Following use as a dormitory, barracks, and then private residence, the original 1792 one-story adobe was expanded with a timber second story and turned into a hotel in the late 1850s. San Juan Bautista was one of the main stage stops between San Francisco and Los Angeles, and the Plaza Hotel, serving as headquarters for the overland stage, and known for its fine cuisine and liquors, became a favorite stopping place for fiesta guests, traders, and travelers. 
Location: San Juan Bautista State Historic Park, 2nd and Mariposa Sts, San Juan Bautista
Listed on the National Register of Historic Places (as resource of the San Juan Bautista Plaza Historic District): NPS-69000038

NO. 181 FREMONT PEAK - On March 6, 1846, Captain John C. Frémont built a fort here on Gabilan (Gavilan) Peak (Fremont Peak). He unfurled his colors and for four days awaited the attack of a force of Californians. The battle did not materialize by the night of March 9, and Frémont broke camp and departed for Oregon.
Location: Fremont Peak State Park, 11 mi S of Hwy 156 via San Juan Canyon Rd (Co Rd G1), plaque located in Abbey Park, SE corner of Fourth and Muckelem Sts, San Juan Bautista

NO. 195 MISSION SAN JUAN BAUTISTA AND PLAZA - Founded June 24,1790, Mission San Juan Bautista, partly destroyed by the earthquakes of 1800 and 1906, was repeatedly restored. The two bells it now uses were salvaged from its original chime. The plaza on its south, surrounded by old adobes, has witnessed many historic scenes, including General Frémont's activities in 1846.
Location: 2nd and Mariposa Sts, San Juan Bautista
Listed on the National Register of Historic Places: NPS-69000038, San Juan Bautista Plaza Historic District

NO. 324 NEW IDRIA MINE - Named for Idria Mine in Austria, the New Idria ranks among the most famous quicksilver mines of the world. Mission fathers, before American occupation, made assays and determined the ore to be cinnabar, mining began in the 1850s, and in 1881 between two and three hundred men were employed.
Location: Plaque located NW corner of State Hwy 25 and Panoche Rd (J1), site located on San Carlos Peak, from Paicines, 30 mi E on Panoche Rd (J1) to New Idria Rd, then 21 mi S to mine