At first glance, an horno does not make much of an impression. Spanish for “oven,” it looks like little more than mounds of mud: Imagine a giant avocado pit halved and placed flat-side down with a window cut out of it. And yet, award-winning designer Ronald Rael wants to build hundreds of these centuries-old furnaces. Pedacito de la Tierra, or A Little Piece of Home, in partnership with the humanitarian-aid organization Alight, is Rael’s third art installment in a series of projects along the U.S. Border wall. In 2009, he…
