The single most recognizable landmark on the San Francisco [1] skyline, the Transamerica Pyramid (600 Montgomery St.) was originally designed to look a little like a tree, and to be taller and prouder than the nearby Bank of America building.
Designed by William Pereira, the pyramid has four distinctive wings, plus the 212-foot aluminum-plated spire, which is lit up for major holidays.
Visitors can no longer ride up to the 27th-floor observation deck (a post-9/11 precaution), but a “virtual observation deck” can be viewed via cameras in the lobby.
Links:
[1] http://www.moon.com/destinations/california/san-francisco-and-the-bay-area