The amphitheaters of ancient Rome were structures that resembled in many respects the stadiums in many of the colleges and cities of the United States.
The structures, both ancient and modern, were erected so that spectators could easily see and enjoy the contests in the large open spaces which they surrounded. But the great difference lies in the nature of the contests.
In the stadium a contestant is injured only by accident; but in the amphitheater the crowds of spectators expected to see bloodshed, gladiators fighting one another to death with swords or other weapons, or infuriated wild animals turned loose upon poorly armed or defenseless human victims.
Therefore, because the hard-packed ground of the old amphitheaters would not soak up the quantities of blood spilled upon it in a contest, it was always liberally covered with sand.
And it was this sand by which the place of combat became known, for arena is the Latin word for “sand.”