Millions of tourists visit the Peruvian citadel of Machu Picchu every year.
It is a World Heritage Site and is increasingly threatened. Tourists leave more than five tons of garbage every day.
In response, municipal authorities are trying to turn the area into the country's first ecological zone.
Mariana Sánchez de Al Jazeera reports from the town of Aguas Calientes, the gateway to the citadel.