Affectionately called the Pyramid, the Transamerica Pyramid was built in 1972 by William Pereira & Associates. Initially, the building was deemed ugly. As startling as it was, the skyscraper is celebrated for its ability to resist earthquakes and wind. Its flexible steel frame absorbs vibrations and its windows are actually set within reinforced panels of concrete! Its tapered shape allows more light to reach street level, minimizing the feel of an urban "canyon." Floor space varies widely depending how high up you are: the 6th floor has 20,650 rentable square feet, while the 48th has only 2,412. A surprisingly lush wooded glen at the Pyramid's base further enhances the city's streetscape. The building stands 853 feet tall or 48 stories high and wears a 220 foot spire on its top which houses ventilation systems. Today, this pyramid stands as one of the most beloved and defining elements of San Francisco's skyline.