Plans to test Amazon's new delivery drones above a "nationally important" Roman road have been branded "horrifying" by campaigners.
Sightings of the unmanned aircraft in the skies over the 2,000-year-old Roman Road and Fleam Dyke trail, near Cambridge, have been reported.
Amazon has refused to confirm or deny whether it is using the land.
But the BBC understands that permission by the UK Civil Aviation Authority (CAA) has already been granted.
There have been sightings from Cambridge Aero Club and land users in the area.
Julia Napier, secretary of Friends of the Roman Road and Fleam Dyke said she was "absolutely horrified".
"The idea of bringing drones to the middle of the countryside is so deeply shocking, one's words fail," she said.
"This is a site of special scientific interest. It is also important as an historical Roman monument.
"People walk here to find peace, the idea that drones can be whizzing over their heads, delivering parcels to people who cannot wait more than two days, who must have the new thing... means more noise in the countryside."
The Roman Road and Fleam Dyke is nestled between the A11 and Balsham.
It is understood that the drones will be tested above the site until October.
The safety of drones has recently come under the spotlight.
There were two near-misses this year between drones and aircraft at Stansted Airport.
A spokesman for Amazon, which plans to offer the new 30-minute delivery system under the Prime Air banner, said they could not confirm testing at the site for "commercial" reasons - but insisted safety was the company's "top priority".