The roof of El Fortin (an old fort and prison above León, Nicaragua) was covered with tanning hides. All pieces were roughly the same size and none were longer than one meter.

The roof was concrete discolored with some form of oil. Dozens of animal hides were being tanned on the roof.

A piece of leather that had been folded twice was now laid flat to dry in the sunlight.

A piece of leather that had been folded was now laid flat on the asphalt roof. Because this was outside, leafs could blow onto the roof and land next to, or on top of, a piece of tanning leather.

A piece of leather was laid next to a ledge where it curled.