The Montgomery Block was built by Henry Wager Halleck, a lawyer who would later serve as Abraham Lincoln's general-in-chief during the Civil War. Critics called it Halleck's Folly, arguing that no one needed so large a building so far from the center of San Francisco. They were wrong. The four-story structure, designed with thick walls and iron shutters to resist fire, became the city's premier office and studio building. Its ground-floor Bank Exchange Saloon was where the cocktail known as Pisco Punch was invented.

Over the decades, the Montgomery Block attracted an extraordinary concentration of writers, artists, and political figures. Mark Twain worked in an office there during his early San Francisco newspaper career. Robert Louis Stevenson visited frequently. Ambrose Bierce wrote there. Sun Yat-sen planned the Chinese revolution from a room in the building. The Block -- or Monkey Block, as locals called it -- became a bohemian community where cheap rents attracted artists and writers who could not afford more respectable addresses.

By the 1950s, the Montgomery Block had been designated for demolition to make way for modern development. Despite protests, the building was torn down in 1959. The site served as a parking lot for over a decade before the Transamerica Pyramid was built on it in 1972. The irony was sharp: San Francisco's most historically significant building was replaced by its most architecturally divisive one. Nothing of the Montgomery Block survives except its stories -- and those, at least, are fireproof.