The word “arena” was passed down to us from the ancient Romans.
To sop up the endlessly flowing blood, the staging area of an ancient Roman arena was made of wood but covered with sand.
“Sand” is harena in Latin, from which the word “arena” was spawned.
Underneath the wood and harena was a dark, noisy labyrinth filled with the stench and noise of prisoners, gladiators, and wild animals, who could “magically” enter the arena by way of a series of trapdoors.