These growths may look like little volcanoes, but they are are nothing of the sort. It's an overflowed electro deposited magnetic nanowire array, says Fanny Béron, who created this work of art in the Magnetism Laboratory at École Polytechnique de Montréal. Using a piece of alumina riddled with microscopic pores as a mold, she grew tiny vertical wires (they look like tree trunks emerging from the ground) from a solution of cobalt, iron, and boron ions. The wires grew through the pores and overflowed, creating the 50-micron-wide mushroom heads seen here. The alumina was then etched away to reveal the "stems" of the mushrooms. Finally, this minuscule scene was imaged with an electron microscope and color was added by an illustrator.