The World Trade Center is a living symbol of man's dedication to world peace.

~Minoru Yamasaki, chief architect

Designed by architect Minoru Yamasaki, the World Trade Center consisted of two 110-story buildings (known as the "Twin Towers") and five smaller buildings. The World Trade Center towers were light, economical structures designed to keep the wind bracing on the outside surfaces.

Architect Minoru Yamasaki studied over a hundred models before adopting the twin tower plan. Plans for a single tower were rejected because the size was cumbersome and impractical. Plans for several towers "looked too much like a housing project," Yamasaki said. The World Trade Center Towers were among the tallest buildings in the world, and contained nine million square feet of office space.

http://architecture.about.com/od/worldtradecenter/ss/worldtrade.htm