Photograph by George Steinmetz / National Geographic "A sea of dunes conjured by wind and water creates a magical sandscape on the northeastern coast of Brazil. Shoals of silvery fish swim in brilliant blue and green pools left behind by the rains. Lagoons are born anew each year after the January-June rains fill the valleys between the dunes. Some of these temporary bodies of water are more than 300 feet long and up to ten feet deep." What an amazing sight! Ten feet deep?! That's a lot deeper than it looks.