Seventy years ago, pill boxes, anti-tank teeth, gun batteries and an array of defensive fortifications began to appear on the county's landscape to protect our coast. So what has happened to those relics of the last war?

“As England, in spite of the hopelessness of her military position, has so far shown herself unwilling to come to any compromise, I have decided to begin to prepare for, and if necessary to carry out, an invasion of England... and if necessary the island will be occupied.”

Hitler’s infamous Directive Number 16, issued on 16 July 1940, merely confirmed what most people in the country had feared for months - that a German invasion of Britain was on its way.

Hitler’s plan, which was codenamed Sea Lion, was scheduled to begin on 15 August. Already acutely aware of their vulnerability and lack of vehicles, tanks and artillery (much of which had been left at Dunkirk), in May 1940 the British Government had begun to devise a strategy that would turn much of southern England into a massive defensive fortress.

Formulated by General Sir Edmund Ironside, Commander-in-Chief Home Forces, the plan sought to create several lines of defence that would at best thwart any German landing or at least slow down the advance should the Germans land successfully.

Under the plan, there was to be a coastal ‘crust’ that was to consist of a thin screen of infantry deployed along the beaches. The aim was to disrupt enemy landings long enough to allow reinforcements to arrive. Behind this a network of stop-lines of various strengths were constructed to slow down and contain any German advance. The final and main position of resistance was the General Headquarters Line (nicknamed the ‘Ironside Line’), which stretched from Bristol, along to Reading, around the south of London and into Kent at Maidstone then into Essex before heading north to end in Yorkshire. This was the backbone of Ironside's coordinated defence plan.

The public has a real appetite to learn more about Kent’s role in the defence of Britain

According to Victor Smith, author of Front Line Kent: The story of the development of Kent's military defences from 1400 to the Cold War, our county in 1940 would have been transformed from the sleepy, rural place it was at the time.

“During this period the county, and of course the rest of the south east, essentially became an intended prepared battlefield, designed to channel an invader into hoped-for killing zones,” says Victor.

“Pill boxes, anti-tank teeth, gun batteries and an array of defensive fortifications began to appear on the county’s landscape. Key points in the defensive plan, such as Canterbury, Maidstone, Chatham and the Royal Military Canal, became heavily fortified.”

Loss of importanceWe all know that in the end the invasion never took place and the war of attrition that General Ironside planned for and feared never came about. Once the war had ended and concerns moved on to other matters, the vast majority of these defensive fortifications lost their importance. Here in Kent, those that weren’t destroyed by local authorities or private landowners were left for nature to wear down.

Most of us have probably driven or walked past those that still remain; strange concrete blocks hidden in the undergrowth or crumbling concrete boxes dotted along the county’s roads.

Local amateur archaeologist Mark Harrison thinks that these relics of the last war have so successfully weaved themselves into the surrounding countryside that they have become almost imperceptible and in doing so hidden their significance from us.

“Lots of people might see these odd little buildings or structures and think nothing of them because they seem to have always been there. But they tell an amazing story and can give communities a great insight into what at the time was a period of real danger for the county. Kent would have been one of the counties to bear the full brunt of the German advance. You can get a lot of this information from books but when you actually come and see something like a pill box; it gives you a sense of immediacy.”

Much of what we now know about the location of the surviving defences has been collected and put together by amateur archaeologists and historians who have started doing this for the simple enjoyment of learning more about Kent’s forgotten frontline.

“I sort of stumbled into this,” says John Guy, who has been researching Kent’s defences since the 1970s. “I had quite a lot of spare time when I first moved to Dover and so spent many hours walking along the cliff tops, and came across many old wartime buildings and lumps of concrete, I wanted to find out what these structures were.

“In doing my research, I found I was researching the cross-channel guns of the Second World War and anti-invasion defences. I found this very interesting. From here I started to research coast artillery and as a sideline, anti-aircraft and anti-invasion defences. I am still doing it and have started to write a book on the coast defence gun batteries around the Dover area.”

What those involved in researching and recording these defences have found is that when given the opportunity, the public has a real appetite to learn more about Kent’s role in the defence of Britain.

Kent would have been one of the counties to bear the full brunt of the German advance

“I’ve given lots of talks and tours about the defences that can be found around Whitstable and I get a really good response from people” says Mark Harrison. “We even put on an exhibition last year at the Whitstable Museum and Gallery, called the Forgotten Frontline.

“The exhibition told the story of how the town prepared for war, its role in the defensive lines and how it faced up to the prospect of a German invasion. Those who came really enjoyed the exhibition. I think part of this interest is attributable to a wider trend that has seen heritage in general become part of the zeitgeist.

Sense of place“But equally, people want to learn about the history of their local community to give them a stronger sense of place. The preparations for invasion were one of the key moments in both Whitstable’s and Kent’s history and because of that, people just want to know more.”

Although around 95 per cent of the county’s Second World War defensive structures have been destroyed, there are still many surviving examples should anyone want to go and have a look for themselves.

“Thanet has a great array of defences still intact,” says local enthusiast Ian Smales. “There are quite a few pill boxes inland that have remained in surprisingly good condition, such as one near the beginning of the A299 Thanet Way, another at the picnic site on Ramsgate Road and a final one near the Swan Petrol Garage in Pegwell Bay. There is also a splendid row of concrete tank traps, known as ‘Dragon's Teeth’ by the side of the road at Pegwell.”

And it’s not just Thanet that’s blessed with examples of these defences. There are many still visible along the Medway, specifically on its bridges, and on the Hoo peninsular.

In fact, across Kent, dotted around the landscape, evidence of what could have been the country’s last hope of resisting invasion can still be found by those willing to take the time to look.

They are the physical reminder of how desperate the spring and summer months of 1940 were and as such one of the county’s most evocative group of historical relics.

Types of defences

Pill box: These were dug-in guard posts (with gaps through which soldiers could fire weapons) made from concrete and brick. The name arose from their similarity to cylindrical medicine boxes

Dragon's teeth: These were square-pyramidal fortifications of reinforced concrete used to impede the movement of tanks and mechanised infantry. The idea was to slow down and direct tanks into ‘killing zones’ where they could easily be attacked by anti-tank weapons

Anti-tank posts: These were constructed from reinforced concrete and were installed at close intervals, in lines, and angled toward the expected direction of enemy attack. Normally situated along the top of railway embankments, they were designed to halt the progress of enemy tanks attempting to climb up the steep side of the embankment onto the track

Demolition chamber: As part of the overall plan to deny freedom of movement to the enemy, many permanent bridges were mined with these. They could be detonated in retreat.

Anti-tank wall: These were the largest of the concrete anti-tank obstacles. Some were built by placing concrete blocks onto a concrete base and then infilling these with more concrete. Others were existing walls which were fortified with concrete. Used principally to block off roads, their size varied depending upon where they were built and the job they were expected to do.