Transamerica Pyramid

The Transamerica Pyramid is the tallest skyscraper in the San Francisco skyline and one of its most iconic. Although the building no longer houses the headquarters of the Transamerica Corporation, it is still strongly associated with the company and is depicted in the company's logo. Designed by architect William Pereira and built by Hathaway Dinwiddie Construction Company, at 260 m (850 ft), upon completion in 1972 it was among the five tallest buildings in the world.

The tower has no public access except for the first floor lobby, thus visitors cannot ascend to the top for a panoramic view.

The land use and zoning restrictions for the parcel limited the number of square feet of office that could be built upon the lot, which sits at the northern boundary of the financial district.

The building is a tall, four-sided pyramid with two "wings" on either side to accommodate an elevator shaft on the east and a stairwell and a smoke tower on the west. The top 64.6 m (212 ft) of the building is the spire. There are four cameras pointed in the four cardinal directions at the top of this spire forming a virtual observation deck. Four monitors in the lobby, whose direction and zoom can be controlled by visitors, display the cameras' views 24 hours a day. An observation deck on the 27th floor was closed after the September 11, 2001 attacks, and replaced by the virtual observation deck. The top of the Transamerica Pyramid is covered with aluminum panels. During the holiday season of Thanksgiving, and Independence Day, a bright, white light is seen on top of the pyramid. The building was built on a special base platform that allows it to reduce shaking from earthquakes. While it gradually reduces shaking, some shaking still intrudes the building.

• The building's façade is covered in crushed quartz, giving the building its pure white color.
• The four-storey base of the building contains a total of 16,000 cu yd (12,000 m³) of concrete and over 300 mi (480 km) of steel rebar.
• It has 3,678 windows.
• The building's foundation is 9 feet (2.7 m) thick and was the result of a 3 day, 24-hour continuous concrete pour. Several thousand dollars in quarters and change were thrown into the pit by observers surrounding the site at street level during the pouring process, for good luck.
• Only two of the building's 18 elevators reach the top floor.
• The original proposal called for a 1,150 ft (350 m) building, which would have been for one year the second-tallest completed building in the world. The proposal was rejected by the city planning commission on the grounds that it would have interfered with views of San Francisco Bay from Nob Hill.
• The building occupies the site that was the temporary home of A.P. Giannini's Bank of Italy after the 1906 San Francisco earthquake destroyed its office. Giannini founded Transamerica in 1928 as a holding company for his financial empire. Bank of Italy later became Bank of America.
• There is a plaque commemorating two famous dogs, Bummer and Lazarus, at the base of the building.
• The hull of the whaling vessel Niantic, an artifact of the 1849 California Gold Rush, lay almost exactly beneath the Transamerica Pyramid, and the location is marked by a historical plaque outside the building (California Historical Landmark #88).
• The aluminum cap is indirectly illuminated from within to balance the appearance at night.
• The two vertical external extensions allow preservation of useful interior space at the upper levels. One extension is the top of elevator shafts while the other is a smoke evacuation tower for fire-fighting.
• A glass pyramid cap sits at the top and encloses both aircraft warning light and a seasonal white beacon.
• At certain times of the year the glass cap will briefly cast a reflected sunlight gleam onto traffic crossing the San Francisco – Oakland Bay Bridge

Source: Wikipedia.org