San Francisco (KGO) -- If you think you know everything about San Francisco... think again.
A new book by Ruth Carlson called "Secret San Francisco: A guide to the Weird Wonderful and Obscure" includes some unusual spots and history that some locals might not even know about.
For example, some say the movie "It's a Wonderful Life" was loosely based on A.P. Giannini, the founder of Bank of America in San Francisco.
San Francisco was also the site of the last known duel in the United States.
And, did you know the city has an official instrument? It's an accordion!
San Francisco is also known for its art scene.
There are lots of great museums including the De Young and SF MOMA, but there's also art just about everywhere across the city.
You can see Diego Rivera murals at the City Club, the Academy of Art Institute and City College of San Francisco.
Rivera was invited to the city in 1930 where he painted his first mural in the U.S. It's called the Allegory of California or the Riches of California.
If you're visiting San Francisco where are some places to visit?
Check out the Camera Obscura at the Cliff House
Mission Murals all over the Mission District
Secret Stairways across town including the Lyon Street Steps and the Sand Ladder near Baker Beach
City Guide Tours from Ocean Beach to North Beach
RELATED: SAN FRANCISCO'S HIDDEN SLIDES
If you're a local check out some of the Privately Owned Public Open Spaces or POPOS located across the city.