caption: The image shows a set of four pieces of stone with moss growing on them, set against a white background. At the bottom of the image, there is some text which reads "Fossilized remains of the remains of a building in the city of San Francisco, California". The stones appear to be aged and weathered, with some of them having a rough texture and others having a more jagged edge. The moss is a vibrant green color, adding a splash of color to the otherwise muted tones of the stone.