I took a section of the city, simplified it, and made a paper pattern of it. Each small city section was given a piece of woolen backing, and dyed cloth, and placed in a ziplock back with the pattern piece. This was my sewing kit for the trip.
Each day in Hiroshima, I would go 'beachcombing' in the river beds at low tide. Although the streets and sidewalks are spotlessly clean, the river held all sorts of objects: many ceramic shards, game pieces, small toys, coins....and glass that had been fused in the blast.
I went to the memorial library, and asked about my project. Were people allowed to find and take these bits of history? An answer came back that yes, they had finished their archaeological search, and I could keep what I found. So I searched, and brought my findings back to our hotel room and washed and scrubbed and then sewed the pieces into the cloth of the map sections. Back at home, I continued sewing (I only finished about a quarter of the map sections while in Hiroshima).