The boom has sparked warnings from heritage experts that fragile sites are crumbling from the sheer weight. Efforts to direct some of the flow away from Machu Picchu has exposed other sites, such as Choquequirao, the "cradle of gold", which are even less well protected.
Locals have complained that the influx is enriching tour operators and luxury hotels but leaving the impoverished communities who live near the architectural wonders with barely two soles to rub together.
Both concerns are valid. Visitor numbers have leaped ahead of tourist infrastructure, no question. Trains, buses and hotels are typically packed. Arguably Cuzco is nearing saturation point. It has half a dozen luxury hotels and at least another four are on the way.
Lax supervision at some Inca and pre-Inca sites leaves them vulnerable, not least to the moron backpacker who proudly showed me a souvenir chiselled from Machu Picchu. A $4 (£2) Pisco Sour in Cuzco, the jumping off point for the Inca Trail, turns bitter when an urchin with an empty belly tugs at your sleeve.
But these are not reasons for tourists to boycott the South American country. Management of archaeological sites seems to be catching up with the influx. The UN agency Unesco no longer designates Machu Picchu an endangered world heritage site.
The government’s strategy of attracting high-spending visitors and promoting lesser-known sites is sensible. Bill Gates, Cameron Diaz and Owen Wilson were recent visitors, helping spread the news that a country once wracked by Maoist guerrillas, hyper-inflation and political chaos is now safe.
When the government’s enthusiasm for tourism seems to go too far local authorities, backed by vocal and well-organised grassroots protestors, have proved adept at creating a fuss and forcing Lima to back down.
The fact that many locals see no immediate economic benefit does not mean Peru is not benefitting. The knock-on effects are real and are helping to fuel a 9% economic growth rate, which should ease the poverty, one of the worst in South America.
Corruption and inefficiency hobble the government but it is democratic and it is directing a fair chunk of tourism-related revenues towards affordable housing, food programmes and job creation.
After suffering upheaval and poverty for so long Peru cannot afford to wrap its Inca sites in a bubble. They are assets which need to be treasured and protected – and used.