The National September 11 Memorial opened to the public on 9/12/11, although it’s not finished. Above, One World Trade Center, also known as Freedom Tower, rises toward its planned height of 105 stories (1776 feet), to be completed in 2013. Below, detail of one of the two pools/waterfalls that mark the sites of the original Twin Towers. By January more than a million people had visited the site. Information here and here.