Cannonballs at the Munchner Stadtmuseum, Munchen (Munich), Bayern, Germany, 2010

I'm not sure which era these cannonballs were from, but they appeared to be stone (this may have been an optical illusion), which could mean either that they were very, very old, or simply that they were replicas. I did note that they were mortared together, although this might have been to prevent vandalism.