A network of Second World War tunnels beneath the White Cliffs of Dover has officially opened to the public, more than 70 years since they were built.

Fan Bay Deep Shelter was constructed in the 1940s as part of Dover's connected offensive and defensive gun batteries, after Winston Churchill requested them for protection from enemy attack.

The shelter, which was personally inspected by Churchill after completion in 1941, was carved out of the chalk in 100 days by Royal Engineers.

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It accommodated four officers and up to 185 men of other ranks.

The shelter had five large chambers with bomb proof accommodation, a hospital and a secure store.

The tunnels are 25m below the surface and cover an area of 3,500 square feet.

The original entrance has been restored and visitors can expect to walk down 125 steps into the shelter.

Video: The tunnels officially open - Jem Collins reports

Fan Bay Deep Shelter was decommissioned in the 1950s and filled in during the 1970s.

A successful public appeal by the National Trust in 2012 to raise £1.2 million meant it could buy the land above the tunnels to start the project.

After two years of conservation by more than 50 National Trust volunteers and a number archaeologists, mine consultants, engineers and a geologist, the tunnels are open for the public to explore.

Two of the first people to emerge from the first public tour today were Becky Macdonald and Paul Hart from Thanet.

Mr Hart said: "It was wonderful to be the first people in. It was fantastic and very interesting.

"It's great to have it open and it's a great tourist attraction for Kent. It's a wonderful piece of accessible history for people to enjoy."

Historic discoveries by volunteers include wartime graffiti such as names of military personnel and socialist slogans, a needle and thread, 303 British cartridges and American 30 caliber ammunition.

Visitors will also be able to see two rare First World War sound mirrors on the site, which gave advanced notice of approaching enemy aircraft.

Gordon Wise, lead volunteer, said: "It’s been thrilling to be involved in the project right from the start. Seeing the tunnels in their raw state when they were first discovered, handling artefacts and giving tours is like standing in the footsteps of history.

"To be part of the digging team, mirroring the work the Royal Engineers originally took to excavate the shelter, was very special. I can’t wait to see what visitors make of Fan Bay Deep Shelter; I hope they’ll surface having experienced something truly unique."

Tours of Fan Bay Deep Shelter will operate daily until Sunday, September 6.

They will then run Monday to Friday until Wednesday, September 30, which may be extended depending on weather conditions.

All tours operate on timed tickets in groups of 12.

The guided tour is 45 minutes in a dark, dirty and wet environment – visitors must be over the age of 12 and in good health.

There is no vehicular access to Fan Bay Deep Shelter and the experience begins with a 45 minute walk to the entrance.

Tickets are £10 per adult and £5 for those between 12 and 16. National Trust members are free.

You can buy tickets on the day from the White Cliffs visitor reception or online. Visit www.nationaltrust.org.uk/white-cliffs-dover.

The National Trust is also asking for help identifying the men from the 172 Tunnelling Company, the 203 Coast Battery and 540 Coast Regiment, Royal Artillery – or any other individuals who served at Fan Bay gun battery and Deep Shelter.

If you can help email whitecliffs@nationaltrust.org.uk or call 01304 202756.