Seventy years ago, secret tunnels below Dover Castle became the nerve centre for one of the most dangerous and desperate operations of the Second World War.

Operation Dynamo was the code-name given to the Dunkirk evacuation, and on May 26 1940, Vice-Admiral Bertram Ramsay and his naval staff worked around the clock to plan and implement the evacuation of thousands of troops - including the British Expeditionary Force - who were trapped at Dunkirk and under fierce attack by the Germans.

What happened over the next nine days was later hailed a miracle as 338,000 stranded soldiers were rescued from the beaches and harbour at Dunkirk, and brought them back to safety.

To mark the anniversary, a week of events is planned in the secret wartime tunnels giving visitors the chance to feel the tension and drama of those days, to see some of the equipment that was used and to experience the conditions in which the servicemen and women lived and worked.

The highlight will be a three-day event, over the May bank holiday weekend (May 29 to 31) when the castle will be occupied by military and civilian wartime personnel as they re-create the frenzy of activity that took place in 1940.

And children will be invited to make individually-named paper replicas of each of the 700 "little ships" that took part in the evacuation to go on display in Ramsay's casement from June 4, marking the final day of Operation Dynamo.

On Friday June 4, a special memorial service attended by veterans will be held in St Mary in Castro church at the castle, before a parade to Admiralty Lookout.

Among those taking part will be members of Ramsay's family and a wreath will be laid at the statue of Admiral Sir Bertram Ramsay which stands next to the lookout, and the castle's guns will be fired in tribute.