White dunes, blue lagoons © WIN-Initiative/Getty Images
From the air, the mesmerizing tapestry of sandy dunes and lagoons you see here gives Lençóis Maranhenses National Park an otherworldly, desert-like appearance. Located in the sparsely populated northeast corner of Brazil, this park gets far too much annual rainfall—nearly 50 inches—to be considered a desert. In fact, heavy rain is part of what makes this place unique: Nearly 70% of its annual rainfall comes between January and May, filling the park"s nearly 40,000 lagoons to the brim with fresh rainwater. Why doesn"t the water sink into the sand? A layer of impermeable bedrock beneath the dunes prevents that from happening.