The ancient Inca city of Machu Picchu is under threat, because too many people are visiting it.
The 15th century Peruvian ruins were discovered in 1911, but landslides and too many tourists are threatening the site in the Andes mountains.
The United Nations have said something must be done to preserve the city.
The Peruvian government have come up with a £68m plan to limit the number of visitors and use satellites to monitor earth movements to protect the site.
If their plan is not accepted by the UN, Machu Picchu would be taken off the list of world heritage sites.
Under the plans, only 2,500 people would be allowed to go to the ruins every day.
But some people say that number is too high, and close to how many people visit already.