Reader's Choice 2007: Photo Galleries

These photos display only a portion of the grandeur and awe-inspiring nature of the which are taller than Niagara Falls, twice as wide with 275 cascades spread in a horsehoe shape over nearly two miles of the Iguazu River on the border between Argentina and Brazil.

Cartagena was one of the first cities founded by the Spaniards in South America. Begun in 1533, the strategic location called for a fortress, and the Castillo de San Felipe de Barajas was started in 1639, but not completed for 150 years. The fortress walls surrounded what is now known as the Ciudad Murallada, or the walled old town, where churches, homes, business and plazas share their colonial heritage.

The three άes du Salut (Islands of Salvation or Health), off the coast of French Guiana are lush, tropical isles of abundant foliage, great views and open to visitors. Once however, they were the site of the infamous Devil's Island penal colony, called the Green Hell. άe Royale is now a resort destination for visitors to French Guiana

Machu Picchu is the most visited tourist destination in Peru, with good reason. The ruins stand atop a steep mountain overlooking the Urubamba river far below, and raise questions archaeologists and historians are still asking. .

The capital of the Inca Empire, Cuzco combines the ancient city, the colonial additions and the modern buildings and amenities in a splendid reflection of culture and tradition of the sophisticated Incan civilization. The ancient plaza was the core of the suyos, the Four Regions of the Inca Empire reaching from Quito, Ecuador to northern Chile.

On a high plateau known as the pampa of San Jose, a tribal group once used the sixty miles long and five miles wide coastal plain to draw long, intricate lines on the desert floor. Pre-dating the Incas, this group disappeared with the Spanish conquest, leaving behind the lines, pottery, gravesites, and more questions than archaeologists and scientists can answer.

Buenos Aires, on the banks of the Rio de la Plata, is composed of neighborhoods called barrios, and most of the sights of interest to visitors are located near the city center, where shopping, nightlife, restaurants, hotels and civic and historic buildings attract both residents and visitors.

Chile's northernmost region, including the provinces of Arica, Parinacota and Iquique, is a natural wonderland of the Atacama desert, Andes mountains and volcanoes, high plains called altiplanos, oases, thermal hot springs and the salars or salt flats that attract visitors from all over the world.

At 979 meters (3230 feet) with an uninterrupted drop of 807 meters (2663 ft), Angel Falls is sixteen times the height of Niagara Falls. Located in Venezuela's Canaima National Park, the falls are best viewed, and appreciated, from the air.

Enjoy these photographs, taken on various NASA and International Space Station missions, of South American cities. Seen from above, the scope, topography, natural landmarks and distinctive features vary in clarity, yet each photograph is a unique way to learn about the city and surrounding area.