A city needs memory like it needs streets, trees, and people. But how do we build an infrastructure to contain and deliver the city's history? Ben Vershbow, former director of NYPL Labs, talks with Shannon Mattern about libraries as stewards of the past in the age of Google Maps.

The New York Public Library’s geospatial librarian Matt Knutzen discusses his stewardship of half a million maps and 20,000 atlases and the contemporary applications of this vast, historical collection.

Gabrielle Bendiner-Viani tells the story behind an innovative memorial to a century-old tragedy with an evolving and enduring legacy for labor rights, building codes and the challenges of commemoration.