A detailed digital model for conservation work at Rochester Castle has been created from drone imagery.
Commercial 'pilot' Geoff Watkins flew his craft over the historic building as part of a partnership scheme with English Heritage and Medway Council.
The model will be used to monitor the castle's deterioration and condition to help with maintenance planning.
Geoff said: "Drones are a lot more than taking photos. They are collecting data that can be used for different means.
"People do not see what is happening behind the scenes.
"People are very nervous about drones but in the right hands they are helping with conservation and other work. It is not all bad."
Senior properties curator for English Heritage, Roy Porter, says the model can be used to zoom into every single stone at the near 1,000-year-old structure.
Experts are then able to plan maintenance or repairs in advance without having someone on the ground trying to assess the condition.
Before this technology, someone would have to climb the building to identify any issues and then return later to address them.
The digital model also captures exactly what the castle looks like today – meaning conservation teams don't rely on out-of-date, older photographs in future.
It took around 1,000 pictures to form the accurate and detailed model including some from the inside.
Geoff added taking images this way avoids the use of scaffolding, ladders and other construction materials, meaning it is safer.
He explained how drones reduce disruption to the sites, and enable images to be captured from places which would otherwise be impossible or very difficult and risky to obtain.
Roy agreed and said it "becomes a challenge" when historical buildings and ruins are so tall like Rochester Castle, which is 113ft high, to assess the condition so using drone technology is a lot easier.
He said: "It is really, really beneficial. It is exciting and the sort of thing that people would not have dreamt of in the Middle Ages."
But not anyone can fly a drone, as you need a licence and permission if using one at an English Heritage site.