You can’t beat a good tunnel for historic atmosphere, and Dover boasts a lot of them. This isn’t surprising. Its cliffs are famously white because they are composed of chalk, which is a nice soft medium in which to plunge one’s pickaxe. That’s part of the reason why, beneath the great medieval shell of Dover Castle, there is a multi-level tunnel network.


The other reason is that this cliff looks out on the Straits of Dover, the shortest stretch of Channel separating Britain from the Continent, and was therefore of immense strategic value down the centuries.

When Napoleon loomed large across Europe (and, indeed, he looked out from Boulogne in 1805 with his Grande Armée massed to attack, but in the end he turned away), Britain needed men ready to repulse him. Dover was thought a likely target, so the medieval castle defences were remodelled and brought into the artillery age. But there wasn’t space to house the men to man the guns. The solution was to go underground.

Tunnels were dug into the cliffs, seven in all, parallel to one other below the cliff-top. By 1803 this ingenious underground barracks was opened, housing at its peak some 2000 officers and soldiers.

Ultimately, Napoleon never invaded, so that might have been an end for the tunnels. However, in 1938, when the threat of war with Nazi Germany hung heavy in the air, the tunnels were brought back into action as the headquarters for the newly constituted Dover Naval Command, charged with protecting the Channel from enemy action.

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It became a rather more important place much sooner than the British military top brass would have hoped, after Germany’s lightning-quick advance in the Battle of France in May 1940 left the entire British Expeditionary Force surrounded and in imminent danger of annihilation, backed up against the wrong side of the Channel at Dunkirk.

Responsibility for getting the stranded army home was dropped on the shoulders of Vice Admiral Bertram Ramsay, head of Dover Naval Command, from his base within those old tunnels. As James Holland says, ‘In 1940 it was a key place because it was where the Dunkirk evacuation – code-named Operation Dynamo – was organised.’

The speed of Hitler’s success meant that Ramsay had precious little time to come up with answers to the terrifying logistical exercise that faced him. Yet over the course of just nine days, starting on 26 May 1940, he and his tunnel-based team orchestrated the evacuation of some 338,000 soldiers in as many Royal Navy vessels as he could muster, along with the now-famous flotilla of civilian ‘little ships’. Churchill called it a ‘miracle of deliverance’, and given that initial estimates suggested that only 45,000 men were likely to be rescued, a miracle it must have seemed.

Before you take the tunnel tour, you’d find it instructive to poke your nose inside the Admiralty lookout buildings on the cliff-top and take in the view of the great harbour below. This is where Ramsay’s lookouts had to monitor the tremendous volume of seaborne traffic during the evacuations. There were so many ships that they had to abandon the naval niceties of harbour management and just let the vessels enter as best they could.

Once you’ve looked out to sea, head down to the tunnels. You’re obliged to take a guided tour for fear of taking a wrong turn (apparently there are, even now, tunnels that have not been fully explored by English Heritage). On your tour, you’ll be taken into areas that have mocked-up re-creations (based on contemporary photographs) of the tunnels’ various wartime uses – from hospital bays and catering corridors to communications nerve centres.

Slightly confusingly, there are more tunnels on show to present-day visitors than existed in the days of Dunkirk. As the Second World War progressed, two further levels of tunnel were added into the network, above and below those created in Napoleon’s time. That original early level, known as Casemate, housed Admiral Ramsay’s control staff in May 1940.

A further level above, Annexe, was dug in 1941 to house hospital facilities; and in 1943 a basement level, codenamed Dumpy, was excavated. On your tour you’ll walk through part of Annexe, then down into Casemate, but Dumpy is off-limits. (There is an instructive film and several good plans of the site to help you get your bearings.)

The tunnels are fascinating places to visit, particularly when you think of how pivotal a role they played in the army rescue from Dunkirk. It’s worth mulling on the fact that in those hectic evacuation days, Ramsay’s staff pulled 24- or 36-hour shifts, working in rather dim light under what must have been pressure of an intensity that’s hard to imagine today. Had they not been able to sort out the logistics of Operation Dynamo so quickly and effectively (and had the German forces moved in for the kill with more rapidity when they had the British cornered), the outcome of the entire war might have been rather different.

If you’re not pining for natural light after the tour, go and take a look at the medieval tunnels on the landward side of Dover Castle, dug in the aftermath of another foreign invasion, when Prince Louis of France besieged the castle in 1216. Admittedly, that foreigner was invited in by the rebellious barons in their battle with King John, so comparisons with Napoleon and Hitler are not strictly accurate, but it does drive home the fact that Dover was, throughout its military history, very much a frontier fortress. In 1940 that frontier must have felt very close to home indeed.

Although the success of Operation Dynamo had at least rescued the bulk of British troops, it was far from clear if that was going to be enough to dissuade Hitler from carrying out his plans to invade.

David Musgrove


Nominated by writer and historian James Holland

Dover War Tunnels
Dover Castle, Harold’s Road, Dover, Kent CT16 1HU
01304 211067


This is an extract from the BBC History Magazine book 100 Places that made Britain, by David Musgrove, published on 2 June 2011.