The Monadnock Building is an historic 10-story, 204,625 square foot office building in downtown San Francisco located at the confluence of the North and South Financial districts and the world-renowned Union Square shopping district. Built in 1907, The Monadnock Building is an exquisite example of turn-of-the-century “Beaux Arts” style and its storied place in San Francisco’s history makes it one of the city’s most well known landmark properties.