If you've ever taken a lunchtime stroll in Lower Manhattan, you've seen them: Sightseers (and locals, too) with their eyes raised skyward, watching the construction of One World Trade Center. Annoying to some, but revealing to photographer Keith Goldstein—whose photo essay Looking On captures the craning.

Goldstein is a professional photographer who has worked in Lower Manhattan for years—he was there when the original WTC fell, and has watched its replacement slowly emerge over the past 13 years. In fact, it was on his own lunchtime walks around the neighborhood that he shot the series.

According to Goldstein, the photos aren't about tourists as much as they are the range of reactions that the new building evokes:

My intention was to capture a thought provoking collection of expressions, emotions, and the diverse ethnic make-up of the visitors. To see how they reacted to what they were seeing – a place where people perished and a new place that was being rebuilt out of the ruins.

The effect is a little like watching people watch a tennis game—there are a few truly vacant expressions, though even those are funny in their own way. But the really great thing about Looking On is how it captures something about a building—about buildings—that an architectural photograph never could.