File:Sentinel and Transamerica Pyramid Buildings San Francisco CA.JPG

• San Francisco, California
  

The timely faded green color of the Sentinel Building exterior, also known as the Columbus Tower, or the San Francisco Flat Iron Building, is juxtaposed against the timeless classic white color of the Transamerica Pyramid Building, framed together with a background canvass of a beautiful clear blue sky in the city of fog - San Francisco, California, USA.

Both buildings visually appear to be opposite in their architectural design, with the Columbus Tower/Sentinel Building having its curvaceous highlights and the Transamerica Pyramid with its, well, triangular punctuation. However, a closer design argument would essentially make the Columbus Tower design "triangular" in shape but standing sideways, with its base as its end side, on Jackson Street, and other angles facing Columbus Avenue and Kearny Street... ;) Both buildings have "rounded tips" that accentuate their triangular shapes from the ground and the air... respectively.

Just a thought to ponder the wonder of a triangle.

The Columbus Tower is owned and operated by film director Francis Ford Coppola and his American Zoetrope Studios, with the Cafe Zoetrope headlining its prime street corner location and offering a bistro style affair along with a wine shop reflecting their Niebaum-Coppola Estate Winery products from the Napa Valley. The Columbus Tower lies on the crossroads of two very characteristic and popular San Francisco neighborhoods of Chinatown and North Beach. The building was built and completed in 1907 and is designated San Francisco landmark number 155. Its distinctive copper-green facade harkens a bygone historical era of 'Flatiron' style of early 1900s American architecture.

Flatiron buildings are structures built between 1880 and 1926, generally in Beaux-Arts or Renaissance Revival architectural designs popular in that era. The buildings are identified as "flatirons" because they are shaped like a flat clothes iron and built on trapezoid-shaped lots common in the 19th and early 20th century city grids.

Another great example of these historic flatirons is the Oakland Federal Realty Building (renamed the Cathedral Building in 1969 due to how it looked), a Gothic Revival masterpiece built in 1914 and was designed by architect Benjamin Geer McDougall, located at the intersection of two of Oakland's main thoroughfares: Broadway and Telegraph. It was recently converted into just seven full floor condominium residences.