Bolivia-Peru: Lake Titicaca
Score: 58

Set high in the Andes, the largest lake in South America thrills travelers with "dramatic scenery" and "fascinating" local culture. Yet pollution from mine operations and untreated sewage is becoming a serious problem, while lakeside towns, especially on the Peruvian shore, suffer from "uncontrolled development."

Here is a representative sampling of additional anonymous comments from the panelists. They are not necessarily the views of the National Geographic Society:

"Lake Titicaca is eternal, but its surroundings are in trouble due to development pressure, and sometimes (ironically) the lack of development. Political issues detract from the pleasure of a visit, but the surrounding region is fascinating if one has a basic understanding of Inca history, the impact of colonialism, and regional copper mining."

"Serious lake pollution has rendered huge areas unattractive for tourism or human habitation. Tijuanacu, however, is an archaeological gem in need of a coordinated international plan for development, exploration, and interpretation. Lack of infrastructure is a serious issue."

"Peruvian side has become quite a tourist trap, despite dreadful infrastructure and the population growth in Puno. The Bolivian side, with the Isla del Sol in particular, is much more authentic."

"The transcontinental highway being built between Peru and Brazil will have a strong impact in terms of bringing more tourism and development to the Puno region."