JERUSALEM — There is one picture of Palestinian children studying around a small table by the dim light of gas lamps in the Beach Camp in Gaza, and another of children peeking over a sandy dune, with rows of small, uniform shacks of a desolate refugee camp in the background. In a third, a family walks across the Allenby Bridge, the father carrying two bulging suitcases, a young son clutching a white ball, heading east over the Jordan River.

These are a few of the black and white images, many of them powerful and haunting, that will eventually constitute a digital archive compiled by the United Nations Relief and Works Agency, the first part of which was unveiled Thursday at a gallery in the Old City here. Together, they capture the Palestinian refugee experience from the 1948 war onward, giving form to a seminal chapter in Palestinian history, identity and collective memory.

For decades, about half a million negatives, prints, slides and various forms of film footage have been hidden away in the archive of UNRWA, the organization that assists Palestinian refugees. Stored in buildings in Gaza and Amman, Jordan, the materials had begun to grow moldy.

So officials started a preservation mission, digitizing the archive, which also documents the work of the agency. The exhibit that opened Thursday, called “The Long Journey,” will soon go on tour to large cities in the West Bank, Gaza, Jordan, Lebanon and possibly Syria, and will also be shown at cultural and political centers in Europe and North America. The images will also be made accessible to the general public on a special website.