By Dan Collyns
BBC News, Lima
The Peruvian government has reversed a decision to allow flights over the Inca ruins of Machu Picchu after an outcry from environmental groups.
Machu Picchu was rediscovered in 1911
Peru's Transport and Communications ministry has declared the area around the site a no-fly zone.
Environmentalists said a number of rare animals and plants would have been severely affected by the low-flying helicopter tours.
Machu Picchu, a world heritage site, is Peru's biggest tourist attraction.
Little more than a week after a licence was granted for helicopter tours over South America's most famous ruin, it was taken away again.
The Transport and Communications Ministry was forced to reverse its decision after complaints from environmentalists and archaeologists.
After a short meeting with Peru's departments of Culture and Natural Resources, the ministry declared a flight restriction in the whole area surrounding Machu Picchu.
Several leading environmentalists said the flights would have caused irreparable damage to the ruins and rare wildlife, such as spectacled bears and vicunas, would have been scared away.
Such flights had been allowed during the 1990s but were banned shortly afterwards.
Peru's Institute of Natural Resources said those flights led to the disappearance of a rare species of orchid and the Andean Condor from the area.
Machu Picchu is one of the best-preserved pre-Columbian ruins on the continent.
But experts say the Unesco World Heritage Site is being slowly damaged by the hordes of tourists which visit it every year.
Meanwhile, the Peruvian government says its investing in a campaign to make Machu Picchu one of the Seven Wonders of the World.