One of San Francisco's unique gems is the Mechanics' Institute, tucked away behind the McKesson building near the foot of Post Street. Originally created in the wake of the Gold Rush to offer technical education for all those scruffy dudes coming down from the Sierras empty-handed, the Institute's current building, constructed in the wake of the 1906 earthquake, is an architectural treasure that houses a chess room, a cafe and event space, and a members-only library with two magnificent reading rooms. The big, comfy arm-chairs are reason enough to join, let alone the knowledgeable librarians and the quarter-million books available to check out - it's basically the cheapest, least snooty private club in town.

If you just want to check the place out, Thursday's day-long celebration of the building's centennial includes tours, refreshments and a variety of talks about San Francisco history.