The glass façade, or curtain wall, of One World Trade Center does far more than let light into the building. In this short video, learn how state-of-the-art glass panels covering the tower offer strength, safety, and beauty to the new skyscraper.

NOVA is produced by WGBH in Boston. Funding for NOVA is provided by David H. Koch, the Howard Hughes Medical Institute, the Corporation for Public Broadcasting, and PBS viewers.