In one of the salt caves of Qeshm island, Iran, Martin Suanjak and me found Pale Rock Martins / Steinschwalben (Ptyonoprogne obsoleta) nesting on pure salt. At least one pair was building a nest on the salt crystal-covered walls inside the cave, some 50 meters away from the entrance. The nest was built from mud that the birds about 300 meters away on the outside.
