porphyry stone floor. pavement of an ancient square in italy. sampietrini stones

architecture cobbles cobblestones geometric granite gray ground italian italy old paved porfido porphyry rome saint peter pietro sampietrini surface tile tiles town traditional vatican vintage squares antique background brick city cobble sanpietrini cobblestone cube cubes floor flooring palladian palladium pattern pavement paving pebbles perspective radially road square stone texture travel urban palladian style city center porphyry ancient italian