These are the Second World War bunkers that still crouch on the landscape as echoes of the biggest conflict in history.
Photographer Jonathan Andrew scoured the wartime territory of The Netherlands, France, Belgium and even Scotland to take these eerie images. He has captured the stern beauty of structures once meant to withstand the fury of war.
The Type 583a / M 178 Fire Control Post at Heerenduin, Ijmuiden, Netherlands: Photographer Jonathan Andrew scoured the Netherlands, France, Belgium and even Scotland to take these eerie images
Type 669 Heenschemolen Bunker, Heensche Molen, Netherlands: The photographer said he started his collection over bunker photos because he 'found the geometry and shape of the structures fascinating'
The Type 703 Emminkhuizen, south of Renswoude, Netherlands: Most of the structures photographed in the set are part of the Atlantic Wall fortifications, but this is part of the De Westwall, aka the Siegfried Line, which sat between Germany and France
The R636 Fire Control Post, Zuydcoote, near Dunkirk, France: The Atlantic Wall fortifications were built in anticipation of an Allied invasion. Mr Andrew says it 'is as if they were still on guard but nobody had told them the war is over'
The SK Observation Tower, Fliegerhorst, Hemiksem, Belgium: This lookout post formed part of a decoy airfield, intended to draw away Allied attacks. It was not a success, the Allies did bomb it - but with wooden bombs...
The Type L483 transmitter bunker, Spaarndam, Netherlands: Graffiti artists have given this inland fortification, just east of Haarlem, a second, less destructive chance at life as a canvas for their typographical artworks
The 42-year-old, originally from Stockport, Cheshire, but now living in Amsterdam, Holland, started his bunker odyssey in 2009 and has now visited them all over Europe.
'I originally found the geometry and shape of the structures fascinating and the fact that they were just left standing alone in a farmer's field or on a beach,' he said.
'It was as if they were still on guard but nobody had told them the war is over. Once I started photographing them it was impossible not to be moved by what the buildings symbolised and what they have witnessed.'
Most of the structures photographed for Mr Andrew's set are part of the Atlantic Wall fortifications, put up by the Nazis between 1942 and 1945 in anticipation of an Allied invasion of the continent from Britain.
The first were chosen simply because the Netherlands-based photographer had noticed them while driving between assignments, and been taken by their surreal, decaying aesthetic.
But subsequently he began to hunt down more and more unusual bunkers dotted around the coast and countryside of north-west Europe.
He researched online, used Google maps and scoured history books in the search for more of these ghosts of Europe's brutal wartime history.
'Obviously a lot of them are the same, so I avoid repeating myself,' Mr Andrew said. 'I choose them by design, concentrating on those which are unusual.'
He added: 'It's almost absurd that these things are still there.
'The shape of them is purely functional, it's just this weird shape and if you didn't know anything about it you would think "what's this?"'
Mr Andrew uses a special technique to photograph his bunkers that gives them their eerie glow, making them seem almost like the apparitions of fallen soldiers.
He explained that each photograph is taking just on the cusp of night-time, in a 15-minute time window just as the last light of the day fades.
Each is the product of a long, 10-minute exposure, with Mr Andrew walking around the structures with a strobe flash to shine light on them from every angle.
He must dress all in black, with his face covered by a black balaclava, as he carries out the lengthy process to ensure that he does not appear in the final image.
'The technique I use when I photograph the bunkers means that I have a 10 to 15 minute window of opportunity to photograph them,' he said.
He explained that he must capture them in perfect light conditions just as day turns to night.
'I walk around the structures with a strobe and flash them,' he added. 'They are very long exposures of about 10 minutes each.'
Mr Andrew says his favourite image is the anti-submarine defences at Cramond Island, near Edinburgh, one of the few in his set to show British fortifications.
'I think that these structures almost look like the Easter Island statues,' he said. 'There's something very strange about them. The pattern they make coming out of the water I find very haunting and I didn't expect there would be any bunker kind of stuff in Edinburgh.'
Another curious bunker photographed by Mr Andrew is the observation tower for a dummy airfield in Fliegerhorst, Belgium.
Alexandre Moretus, current owner of the land in which the bunker sits, told him: 'Did you know this observation tower was a part of a decoy (fake) airfield intended to distract allied air attacks.
'This was not a success in this case... The allied bombed it but... with wooden bombs.'
The Military Casemate Type 623, West of Koudekerke, Netherlands: the Atlantic Wall was begun in 1942, following the devastating raid by British commandos which destroyed the dry dock at St Nazaire, and strengthened in 1944
Type V143 Mammut Radar Antenne, Waringzelle, Nord Pas de Calais: Field Marshal Erwin Rommel ordered the second phase of building because he believed Germany could not resist an invasion of Europe were it not stopped at the beach
The Dragon Teeth, Riegelstellung Dune, BPT: Used to slow down tanks and mechanised infantry, landmines were often placed between the teeth
We had some defences too: The Cramond Island submarine defence boom, near Edinburgh, Scotland, which are Mr Andrew's favourite in the entire collection
The photos were not taken to make an anti-war statement, Mr Andrew said, but to offer an insight into a fascinating chapter in history.
'As a photographer you try and point things out to people which you find beautiful or fascinating and ask them to take a longer, closer look,' he said.
'I'm not trying to make an anti-war statement but just bring them to peoples attention, show people these amazing buildings, steeped in such incredible history are still scattered throughout Europe's fields and dunes.
'I work on the bunker photographs only in the winter, it's taken about three winters to photograph the collection so far. It's a personal project, so I have to find time between my regular paid assignments.
'It's surprising to see some bunkers being used by farmers for other purposes, such as storing animal feed, farm equipment etc. I'm also amazed at the shear number of them still around, some in very good condition.'