Memory-haunted arena of the ancients, Rome’s 1,900-year-old Colosseum saw bloody gladiatorial duels, battles with wild beasts, and mock naval engagements on its flooded floor. Christians banned the spectacles, and in later centuries presented church dramas here.

Time, earthquakes, and stone scavengers took their toll. Still, the treasured monument survived and at the time of this photograph was still serving Rome—as a traffic circle.

Cars at evening rush hour create streaks of light in this time exposure, which also captures horse-drawn carriages waiting at curbside for tourists.

—Text adapted from "When in Rome," National Geographic magazine, June 1970