A woman sells tickets to a tour of the United Nations (May 12, 2006) at the United Nations headquarters in New York. The United Nations headquarters, completed in 1952 and largely unchanged since, is widely considered to be a landmark achievement of the International Style of architecture, a style that reached a massive climax with the construction of the World Trade Center 20 years later. Tours in many languages are given most weekdays at the U.N.
More information about U.N. tours is available here.