A large sandy area, speciﬁcally a place too sandy for planting but not sandy enough to produce dunes. The word is occasionally used to designate a place where quicksand is found, but the proper expression here is arena movediza, literally “movable sand.” Arenal is from arena, Spanish for sand, though in English that word is commonly used to designate a ﬁeld set aside for athletic competition. The connection lies with the Roman practice of using sand (harena in Latin) in amphitheaters such as the Colosseum, primarily to soak up blood. The sandy surface in a modern bull ring limits the bull’s ability to turn or to surge quickly, and heightens the impression of force and action when it ﬂies up from the bull’s hooves. Only incidentally does it soak up blood.