She heads New York City’s Landmarks Preservation Commission, safeguarding 36,000 buildings. She loves them all, of course, but one material has a special claim on her heart. “We have terra cotta everywhere in this city, architectural terra cotta. It’s structural, it’s non-structural, it’s ornamental.” That fabulous clay, that magical goo, that stuff that makes Manhattan. A conversation on the built environment. Produced with the Municipal Art Society.