Leaving Rome’s famous Colosseum today I noticed this hole carved into one of its corners. It struck me as a reminder of the building’s uses through its 2000 years. Someone had dug out that hole (in what century who can tell?) so that they could tie their donkey or horse. They did it so many times that the stone (travertine; a limestone) was worn to a glassy smoothness. Perhaps the stone merchants, who for a thousand years quarried stone from the building, roped one of their pack animals here as they loaded the marble slabs from the seats of the giant structure.