The Iguazu Falls are one of the most spectacular sights in South America. Situated in the national park called Parque Nacional Iguazú, the falls lie along the Iguazú River, which separates Brazil and Argentina. The falls get their name from a Guarini (South American Indian group) word that means "great water." It's no wonder since the horseshoe-shaped falls are almost 2.5 miles wide-four times the width of Niagara Falls! (MARC SHANDRO—GETTY IMAGES)