Fan Bay Deep Shelter at The White Cliffs of Dover

The interior of Fan Bay Deep Shelter in The White Cliffs of Dover in Kent, showing its arched corrugated steel construction — Looking into the officers' accommodation tunnel at Fan Bay Deep Shelter at White Cliffs of Dover, Kent , showing its arched corrugated steel construction | © National Trust Images/Chris Tapley

Completed in just 100 days, Fan Bay Deep Shelter provided shell- and bomb-resistant accommodation for the soldiers serving on the nearby gun battery in the Second World War. After a mammoth volunteer rediscovery and reconstruction effort, visiting the shelter is now a highlight of many trips to The White Cliffs of Dover.

Visiting the deep shelter

Our 2024 season has now ended. Thank you to everyone who visited us this year. Fan Bay Deep Shelter will re-open for the 2025 season on Monday 31 March 2025. We're looking forward to seeing you then.

Your visit

You can experience the shelter just as the soldiers did over 80 years ago. Your visit to Fan Bay Deep Shelter will be a unique and inspiring experience. You’ll be inside the tunnels for around 45 minutes, and you will be wearing a protective helmet with a head torch, which will provide lighting for your journey.

Steps into the past

After your safety briefing, you descend the 125 steps into the shelter. Your knowledgeable and friendly guide will show you wartime depictions of the scenes within the tunnels and artefacts and graffiti left by the soldiers and those who followed. You can look at the vain attempt at dismantling the shelter by the scrapman and admire the fossils in the chalk. Halfway through your tour you will emerge into daylight to see the two sound mirrors – relics of an earlier conflict. You'll complete your tour by going back underground, through the longest tunnel in the complex, before you climb the stairs and head back into daylight once more.

Views of the deep shelter

Some of the features you'll be able to see when you take a guided tour of Fan Bay Deep Shelter.

Image of a guided tour descending the stairs into Fan Bay Deep Shelter, The White Cliffs of Dover, Kent — A guided tour descending the stairs into Fan Bay Deep Shelter, The White Cliffs of Dover, Kent | © National Trust/Chris Tapley

A guided tour descending into Fan Bay Deep Shelter

The staircase of 125 steps in three flights is the original concrete and steel structure that the soldiers would have used to enter the shelter. You can almost sense the relief that they would have felt as they rushed to take cover from shells from the German guns on the French coast, just 20 miles (32km) away, or the enemy aircraft with bombs and machine guns, directly overhead.

A guided tour in one of the accommodation tunnels

Excavated by the Royal Engineers in the winter of 1940/1, the accommodation spaces contained the bunks where the troops would sleep when off-duty. You can feel the chill and the damp the soldiers experienced when in the shelter. The tunnels were supported with steel frames called colliery arching (colliery is another term for a coal mine) and were lined with mining-grade corrugated iron. The lining is held in place by the sheer weight of the chalk, packed above and to the side by the miners, to support the chalk above.

Image of a visitor to Fan Bay Deep Shelter examining one of the fossils in the chalk — Visitor to Fan Bay Deep Shelter examining one of the fossils in the chalk | © National Trust/Chris Tapley

Clam shell fossil

During your tour, look out for fossils in the chalk. This one, in the roof of one of the chalk passageways in the shelter, is a fossilised clam shell. Living on the seabed over 80 million years ago, this lovely specimen reminds us of the geological turmoil that has occurred since then. The fossil is now nearly 230ft (70m) above the sea. Look closely as you walk around and you may see some more. Look out too for the flints in the chalk - shining like black diamonds in the moist surroundings, they too began their existence on the seabed at the same time as the fossils.

Image of the 1917 sound mirror at Fan Bay, Kent. A later one, built around 1920 is shown below. The two Fan Bay mirrors, which were redundant by the Second World War formed a convenient platform for drilling of deep shelter's tunnels. — Image of the 1917 (northern) sound mirror at Fan Bay, Kent. | © National Trust/Chris Tapley

The sound mirrors

Built in early 1917, the northern mirror features in the diaries of the First World War as it detected an incoming air raid, potentially saving hundreds of lives. It was one of the first sound mirrors to be constructed. Built of reinforced concrete. the mirror reminds us of the very early days of aviation and our efforts to detect incoming enemy aircraft without the use of electronics. The mirrors had a clear view out into the English Channel when they were built. The brickwork and soil in front of the mirrors now is from the Second World War structures and their subsequent burial in the 1970s.

The plant room

After a serious condensation problem forced the soldiers out of the accommodation tunnels, a powered ventilation system was installed. The plant room, built in the winter of 1941/2, housed a heater and an electrically driven fan to force dry air into the tunnels, powered from a nearby engine house. Today, we use this room to welcome our visitors and you can see the original fan as well as photographs and plans from the Second World War and from our rediscovery project. Although it's not part of our guided tour, just ask one of our guides to show you around.

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Helpful advice

Tickets are sold at the tunnels site on a first-come-first-served basis and we cannot reserve places on specific tours. Due to a lack of mobile phone signal, we cannot accept card payments at the deep shelter. If you wish to pay by card, or if you would like to check tour availability before walking out, please ask at the Visitor Centre shop, near the car park, or at the South Foreland Lighthouse shop.

If you are parked in our additional parking area and wish to purchase tickets for the tunnels by card, please ask the attendant at the car park hut, who can take your payment and issue a receipt for you to show at the tunnels. National Trust members with valid membership cards can visit for free. Please check our opening days and times on the White Cliffs home page before travelling.
Tours normally start every 30 minutes on the hour and half hour between 11am and 3pm and last for approximately 1 hour. Our guides will ensure your safety, show you around, and tell you the story of the entire tunnel complex, together with the sound mirrors. We've tried to conserve the tunnels as they were, so even in the summer, they are cool and damp and the floor can be slippery in places - please take care. We'll provide you with a hard hat and head torch, and you’ll need sensible shoes with closed toes. No flip-flops, sandals, or high heels, please.

Full details of tour times and dates are on our home page.
The tunnels are accessed using the original staircase of 125 concrete steps, descending or ascending 23 metres (75 feet). The staircase has floor-level lighting and a handrail, and you’ll be encouraged to take the stairs steadily. If you are unsure about the staircase, please ask to see it before you decide to take a tour.

There will be a noticeable temperature change on the staircase as you enter and leave the shelter. The tunnels are unlit, but your head torch will give an adequate level of lighting. Most of the tunnels provide enough height and width to enable upright walking throughout the tour, although some crouching down is needed in a couple of short sections, particularly if you are tall. Please ensure you take any medication you may need into the shelter. If you feel uncomfortable or unwell at any stage during your tour, just let your guide know.
Assistance dogs only are welcome at the deep shelter. Please be aware that some dogs can become unsettled in the tunnels due to the enclosed, dark surroundings and unfamiliar smells.

Our tours are child-friendly. We must cater for everyone on the tour and very young children may find the stairs challenging and some of the presentation content difficult to absorb. We advise a minimum age of 8 years. We have a number of child-sized hard hats and head torches for their protection. It is not possible to carry babies or very small children into the shelter, owing to the risk of injury, should a fall occur on the staircase.

Image of a National Trust guide explaining a picture of the tunnels during wartime to visitors at Fan Bay Deep Shelter — A National Trust guide explaining a picture of the tunnels during wartime to visitors at Fan Bay Deep Shelter | © National Trust/Chris Tapley

The history of the Fan Bay battery

From Churchill's speech, to the construction of the gun battery and the deep shelter. From their use during the Second World War and subsequent abandonment. From the demolition and covering over in the 1970s to the rediscovery and opening and the subsequent unearthing of the plotting room and the gun emplacements. Find out lots more about the history of this almost forgotten relic of wartime and how we rescued this priceless artefact on our special page 'A brief history of Fan Bay Battery'.

The Fan Bay sound mirrors

With Louis Bleriot’s epic flight across the channel in 1909, the Dover Strait no longer offered our island nation security from attack. During the First World War, Britain came under aerial bombardment for the first time and new ways of protecting ourselves were needed.

The first sound mirror experiments were conducted in 1915 using ‘dishes’ cut directly into chalk at a quarry site near Maidstone, Kent. These early attempts soon gave way to larger, more complex concrete structures, faced with smooth cement. Sound mirrors became relatively common around the south and east coasts of England coast from Hampshire in the south, to County Durham in the northeast. The first Fan Bay mirror was built in 1916/17, the other around 1920.

How sound mirrors work

Sound mirrors used a curved surface to concentrate the sounds generated by the aircraft’s engine, reflecting these into a funnel-shaped collector to which was connected a stethoscope. This increased the range at which the aircraft could be heard. A specially trained operator would listen intently for the distant noise and warn of a potential air raid, giving an estimate of height and bearing. Many lives were reportedly saved in the Dover and Folkestone area in 1917 by the earlier sound mirror.

Over a decade after the first mirror was constructed, the collector would be replaced by a sensitive microphone and the stethoscope by an electronic amplifier and headphones. The mirrors were superseded by radar in the late 1930s.

Visiting the sound mirrors

Your guided tour of Fan Bay Deep Shelter includes a visit to the two sound mirrors at Fan Bay. You can even try out the sound mirror effect for yourself on our specially designed platform.

Image of the southern sound mirror at Fan Bay Deep Shelter — The southern sound mirror at Fan Bay Deep Shelter | © National Trust/Richard Meadows

Captain Strange and Fan Bay

Visiting Fan Bay has become an even more exciting experience as a wartime leader of the battery has been brought to life by one of our dedicated volunteers.

Arthur Lionel Strange was born in Wolverhampton in 1920. He joined the army at 18 years old and was commissioned as a second Lieutenant in 1941. Strange took command of Fan Bay Battery in August 1944 and was promoted to Captain, Temporary Major. He remained in command at Fan Bay until early 1945.

Unfortunately, like the deep shelter, Captain Strange became somewhat forgotten and unknown. Fan Bay’s amazing re-discoveries has led to a quest for knowledge of the site and its key role in the outcome of the Second World War.

Volunteer Gordon Wise as Captain Strange who commanded Fan Bay Battery from August 1944 until early 1945 | © National Trust/Duncan Wood

Meet ‘Captain Strange’

On selected days from April to October, Gordon Wise, one of our volunteers who led the excavation of Fan Bay Deep Shelter, helps to bring Fan Bay to life. Sporting an accurate replica uniform, Gordon enjoys sharing his wide knowledge of the history of the area with our visitors.

'Captain Strange' is now taking a well-earned winter break. We look forward to seeing him again in 2025.

An image of a footpath snaking through fields at the White Cliffs of Dover in Kent with the white tower of South Foreland Lighthouse poking out over the top of the hill

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Fan Bay Deep Shelter at The White Cliffs of Dover