This 14-story office building (1903, Willis Polk) was the focal point of commerce in c.1900 San Francisco. Signals from its rooftop belvedere announced the arrival of ships through the Golden Gate. Badly damaged in the 1906 fire, it was quickly restored. Prolific architect Julia Morgan maintained an office on the 11th floor for most of her 46-year career.From the Ionic columns at the entrance, walk though the barrel-vaulted elevator lobby to the commodious Grain Exchange Hall. Here, beneath marble columns and gilt capitals, merchants and traders convened to transact business. On the walls are 13 paintings by marine artist William Coulter, depicting the intricately rigged sailing vessels that once commanded San Francisco Bay