CLEVELAND, Ohio - Founded in 1796, this city is a relative youngster by global standards, but it has changed radically in many respects.

The downtown skyline bristles with towers that didn't exist half a century ago. The onetime back door of the Cleveland Museum of Art is now enclosed under a vast atrium. And concourses at Cleveland Union Terminal have become shopping promenades of The Avenue at Tower City.

Those are some of the changes recorded by Cleveland photographers in "Impermanence," an exhibition at Heights Arts Gallery, 2175 Lee Road, Cleveland Heights.

Organized by Daniel Levin, an associate professor of photography at Cuyahoga Community College, the show is based on a simple premise.

Levin introduced his students to the photograph collection at the Cleveland Public Library and asked them to pick a half dozen for closer study.

Once they had chosen, he said he asked them to scout the locations of each image, and to re-photograph the scenes from as close as possible to the viewpoint of the original photo.

Re-photography is a time-honored practice used to record change over time in historical settings or landscapes.

Levin said he was so pleased with the results that he decided to ask other well-known Cleveland-area photographers to engage in the same activity and to combine paired historical and contemporary scenes by both sets of photographers in the same exhibition.

The results, on view through April 18 at Heights Arts, survey everything from familiar spaces and places such as Public Square to interiors of homes or alleyways in Cleveland Heights and Shaker Heights.

"Bricks and mortar are permanent yet impermanent," Levin said, "especially in America, where we tear things down more than Europe does."

Levin's students were assigned primarily to examine photographs of architectural settings, rather than people. But he said he was especially struck by a pair of images of Cleveland's City Council, taken in 1924 by an unknown photographer and in 2015 by David Hagen.

The first image shows a packed chamber with every seat filled in every row, including the balcony in the distance.

In Hagen's contemporary photo from the same point of view, a council that has been vastly reduced in size because of population shrinkage barely fills the chamber, and the balcony is empty.

Another pair of images, showing a trio of houses on West 14th Street in Tremont, shows a 1967 scene by an unnamed photographer alongside a 2014 photo from the same spot by Victoria Stanbridge.

Levin said the pair of images contradicts usual assumptions about urban entropy because the contemporary image, shown to the right of the older shot, shows that the three houses are in better shape now than they were a half-century ago.

"Everything in the one on the right is more loved, more cared for," Levin said. "I just love that about it. It gives you hope."

Other signs of change are amusing. Photographer Mark Holz recorded a 2015 image of the intersection of Taylor and Cedar roads in Cleveland Heights, which shows that the building now occupied by Melt, the eatery that specializes in melted cheese sandwiches, once housed Max's Discount store.

Change -- or impermanence -- is the constant theme.

Yet Levin said that for him, the show provides convincing evidence of the importance of historic preservation.

"A project like this can make people appreciate the old before they tear [down] and demolish," he said. "It's just a personal feeling I have that drives me to be interested in these projects."