To Blair Kamin, the Pulitzer Prize-winning architecture critic of The Chicago Tribune, the wrought-iron gates that ring the campus green at Harvard University in Cambridge, Massachusetts, are more than decorative. They are storytellers through design and time capsules of university history, which he and the students he taught as a fellow at the school’s Nieman Foundation for Journalism explore in the book “Gates of Harvard Yard” (Princeton Architectural Press). Its thoughtful essays examine the 25 gates surrounding the yard, popular with tourists as well as students, alumni and staff. The following are excerpts from an interview with Kamin, the editor of the book.

Q: You could have covered other interesting architectural features at Harvard. Why gates?

A: The gates really sound the opening notes in Harvard's architectural symphony, and yet most students and tourists pass by them in their rush to write the next paper or pose for selfies alongside the John Harvard statue. I wanted to dig deeper and find out what these portals were all about.

Q: You call them "carefully wrought constructions that direct human movement and uplift everyday experience." How?

A: In the same way that a funnel channels the flow of water, gates funnel the flow of people, but they do so with great artistry, and that's how they enrich everyday human experience. One of my favorite gates is the Dexter Gate. Above the entrance is an inscription that's often quoted, "Enter to Grow in Wisdom." And that inscription summarizes the passage from ignorance to wisdom that a university education is supposed to be all about. Most of the gates were designed by McKim, Mead & White, a great architectural firm, and they are a family, a series of theme and variations whose materials are brick, wrought iron and stone. So if you stop and look, you see things like a cross that represents Harvard's commitment to training ministers, or you'll see delicate flowers and leaves made of wrought iron that extend the pastoral identity of Harvard Yard out to the street.

Q: Why was McKim, Mead & White chosen, and did its involvement lend continuity to the Yard?

A: McKim, Mead & White was the great establishment firm of the era. They designed New York's Pennsylvania Station, the so-called cottages of the rich in Newport, Rhode Island, and the Boston Public Library. They were the go-to firm for an institution like Harvard. The first gate, the Johnston Gate, was built in 1889, which was more than 250 years after Harvard's founding in 1636. The gate was really a turning point in Harvard's architectural history. The architect Charles McKim rejected the florid, multicolored, Victorian Gothic style of Memorial Hall and instead turned back to the colonial Georgian-era buildings as his inspiration.

Q: What surprised you most about inspecting the gates so closely?

A: Just how beautiful they are. They keep giving you new details that enrich the experience of looking at them. For example, there's a gate that's dedicated to Charles William Eliot, the long-serving president of Harvard, and if you look at the wrought iron in that gate it has a whimsical nod to Eliot's Pilgrim ancestors with a little Pilgrim's hat. The contemplative atmosphere of the yard would not be the same if not for the gates and the fences that delineate a barrier between town and gown. Harvard Yard is surrounded most typically by a fence so it's visually transparent. You get a sense of the beauty of the yard, the buildings, the sculptures, which are all accessible to passers-by as they walk along even outside the gates.