Assuming we're in Lima, Peru, Messner is probably talking about Machu Picchu, or one of the other Inca sites.
Machu Picchu is an abandoned fifteenth century Incan town in Peru. Its beautiful situation high up in the mountains above the Urubamba Valley, combined with its impressive state of preservation, make it one of the most popular tourist destinations in the country.
Machu Picchu was voted one of the Seven Wonders of the Modern World in 2007. The site is an extremely lucrative source of income for Peru, but in recent years concerns have mounted over the impact high volumes of tourists are having on Machu Picchu's preservation. UNESCO, who gave the site World Heritage status, are currently considering putting it on the list of endangered heritage sites.