A robot dog called Spot is being used to survey buildings that were once used for weapons testing during the Cold War.
Spot - a robot with four legs and a camera mounted to the top - is controlled remotely to explore spaces where it is unsafe for humans to go.
The experimental tech was brought in to inspect two labs in Orford Ness, Suffolk, which have been deserted for years due to decaying concrete making it unsafe.
The remote shingle spit was used as a military test site during both world wars, and into the nuclear age.
The buildings were constructed in 1960 to carry out environmental tests on the atomic bomb - mimicking what the weapon might face before being detonated, including vibration, extremes of temperature and shocks.
Although no nuclear material was involved, a test failure could still have resulted in a catastrophic explosion.
For this reason, the labs were designed and constructed with a shingle top which would absorb and dissipate if an explosion occurred.
The Ministry of Defence sold the site to the National Trust in 1993.
Glen Pearce, operations manager at the National Trust’s Orford Ness, said: “The buildings have always had a certain mystery about them.
“When they were built and in use during the Cold War, they were shrouded in secrecy, and after they were decommissioned, they fell into disrepair.
“Nobody has been able to go inside for several years due to safety reasons."
Drones were also used to survey the decaying sites, known as pagodas or Labs 4 and 5.
National Trust archaeologist Angus Wainwright said: “The buildings used to be quite safe so we could go in and out as much as we liked, but now they are getting more risky as the concrete decays.
“That’s why we are doing this survey in this remote way, without anyone going into the buildings.
“It’s all very experimental, to see if it’s possible to do a really detailed building survey with no human operator in the building.
”The structures are part of the National Trust’s curated decay policy and have been left to nature, with their roofs becoming nesting sites for lesser black-backed gulls, which are on the UK’s amber conservation list."
Want a quick and expert briefing on the biggest news stories? Listen to our latest podcasts to find out What You Need To Know