The New View From the Top of One World Trade Center N and finally tonight, the view of a resilient city. When completed, it will be the tallest building in the western hemisphere, a summit of rebirth and renewal. Tonight abc's bob woodruff takes us for the first time to the observation deck of the new 1 world trade center. Reporter: Here on the southern tip of manhattan, there's a new tower, taller than the empire state building, the highest in the entire western hemisphere, and it rose from the dust and ashes of tragedy. Where millions of visitors will be able to see new york in full panorama. We did get the chance last year, one of the first, to make&#231;&#243; it to the top. Then, there were no windows or walls, but today there is glass. Our look out on the world is back. Reporter: It will be three floors high, a restaurant, video displays, and the most breath-taking view. What we have to remember is that 25,000 workers who helped to build this record-holding high-rise. Who moved so much earth and steel to bring us this heavenly view. Reporter: So many of these workers told us, this is not just a project. It's a gift that I personally felt like I give this country, for giving me the opportunity to be here. This building is so emotional for me. You can't I feel. I really feel proud.