For more than two decades, Camilo José Vergara has taken photographs of hidden Chicago spots that he fears would be forgotten without the attention of his lens.

During a workshop called, “Unexpected Chicagoland,” Vergara described the motivation that led him to write a book about those undiscovered locations to a group of 12 professors and graduate students on Thursday at the Kaplan Center for the Humanities.

Vergara, a photographer and sociologist, is writing the book with Timothy Samuelson, curator of architecture and design at the Chicago Historical Society.

The presentation included a wide range of photographs and anecdotes on areas of Chicago and Gary, Ind., that will be featured in the book expected to be published next year.

The workshop was part of the series, “The Culture and Society Workshops,” offered weekly to faculty and third-year graduate students at the Kaplan Center.

Vergara presented several of his own photographs while Samuelson provided stories that complemented each scene. Vergara began by showing areas of the city, once marked with buildings, that now are bare. These photographs, he said, preserve periods in Chicago’s history that otherwise would be forgotten.

“How quickly so much of Chicago has disappeared,” Vergara said.

Another topic Vergara addressed was Chicago area signs, such as those in front of restaurants or on bulletin boards. Both Vergara and Samuelson pointed out that many lasting signs in Chicago have remained since the 1950s.

“The signs were choreographed like a fine dance,” Samuelson said.

Vergara used photographs of Chicago housing projects to give insights into people’s lives. For example, he said, people who live in the housing projects use hallways for everything, from teaching their children to ride their bikes to holding resident meetings.

Vergara has written several other books, including one on cemeteries in inner cities and another entitled “American Ruins.” His best-known work is “The New American Ghetto,” in which he shows the urban decay in areas like the South Bronx, Harlem, Newark, N.J., Detroit and South Central Los Angeles.