As you look across the county's predominantly green and pleasant land, it is easy to overlook a hidden part of Kent - that which lies beneath our feet.

In pretty much all our major towns and cities there are labyrinths of tunnels many created when Britain was at war - others dating back centuries.

We take a look at some of those places you may not even know exist (and certainly shouldn't attempt to visit unless given permission).

Rochester's Short Brothers Tunnels

The romantic within us would like to think the maze of tunnels which weave their way beneath the medieval city of Rochester were carved hundreds of years ago. The reality, is they are a 20th century construction but are no less impressive - if no longer accessible - as a result.

The famous Short Brothers company was a pioneer of aircraft manufacture and in 1941, during the Second World War, demand for their services was increasing.

Granted permission to expand its existing base, they built an underground facility which was capable of withstanding aerial attacks but proved a safe haven during raids for its workers.

The result was a series of tunnels culminating in a number of expansive spaces where the planes were manufactured.

When the company moved out it changed hands - finally to road paving firm Blaw Knox before its closure in the 1990s. Today access to the site has either been blocked or requires permission due to the dangerous conditions within.

Hollingbourne Zero Station

Accessed by a hatch which looks like it belongs in TV show Lost and lurking in woodland lies a relic of our wartime Britain - preparation for a German invasion.

A step ladder leads down into a number of underground rooms - accessed by what was originally a secret door to fool any patrols into thinking it was just a store room.

During the war the Auxiliary Units Special Duties Organisation was established. By recruiting non-Army figures, particularly those who would be expected to move around the country for the purpose of their job, their role was to provide information to feed into a resistance movement against invading forces.

As a result, everyone from vicars to postmen, farmers to doctors were trained how to collect information and then leave their reports in 'dead letter boxes' for collection - such as discarded tin cans or trees.

Trained to help sabotage German forces if they arrived on our shores, the purposes of these buildings, which were built around the country, was for the information to be collected and then transmitted to a central unit in Wiltshire to track German troop movements and spy on their progress.

Today the site is abandoned.

Canterbury battle headquarters

During the early 1940s, the Army constructed a number of underground complexes as part of a co-ordinated command operation. Tunnel systems were created in Reigate, in Surrey, Tunbridge Wells, Canterbury and Sarre, in Thanet.

All were fully fitted out with power and equipment, although it remains unclear if they were actually used during the conflict.

The Canterbury site is today in a state of partial collapse, as is the site in Sarre.

Dover's war-time tunnels

The county's main entry point for foreign visitors is certainly no stranger to underground tunnels - indeed Dover Castle has long since turned its war-time control rooms – originally created in the event of an invasion by Napoleon - into a popular tourist attraction.

But there are a host of other tunnels built into the cliffs which ring the coast and used, in times of conflict, to station soldiers or look-outs.

At a former quarry site - called Winchelsea Caves - a series of tunnels were built during the First World War to test a drilling machine which was to be deployed on the Western Front. The result proved a useful refuge for townsfolk to avoid bombing raids in the Second World War, with more than 1,300 people using it for shelter. It is said, in 1944, that even King George VI and his Queen took refuge there when the air raid sirens sounded during a visit.

Then there was Dumpy B communications bunker at Langon Hole, built in 1942. One of two underground wireless outstations in the town, the tunnels included accommodation areas, a generator and the communications hub. Today, asbestos has been disturbed making the tunnels dangerous to enter.

Folkestone's naval bunker

At the end of the Road of Remembrance is a building which leads into a host of tunnels and rooms built into the cliffs.

The bunker was constructed during the Second World War where it was used as a Naval communications centre - passing on information from coastal shipping radio traffic to the code-breakers at Bletchley Park.

Consisting of a host of thick-walled rooms, reached by descending staircases, remains of war-time posters can still be seen on the walls.

Once a thriving hub, today it remains abandoned, derelict and sealed up.

Ramsgate Tunnels

OK, the chances are you'll be aware of the Ramsgate Tunnels if you live in Thanet, but they still make for a fascinating visit and their sheer scale is something to behold.

Starting in a Victorian railway tunnel visitors can now get a guided tour as they follow the labyrinth of passageways which were used to protect the good folk of Ramsgate during the bombing raids of the Second World War.

Capable of housing up to 60,000 people, many took refuge during the attacks - with plenty opting to live there for the duration.

The further in you go, the more you find yourself beneath the town itself.

Once a popular place for youngsters to discover and graffiti, now it's a thriving tourist attraction.

Darenth Wood Denehole

Not so much a tunnel system, but a fascinating and mysterious underground structure which continues to prompt debate as to its original purpose.

Deneholes manage to still make the headlines due to the fact they are often responsible for large sinkholes opening up as a result of them - most notably on the M2 in 2014 between Faversham and Sittingbourne.

In Darenth Wood, near Dartford, there is one such, intact, example. Like others, they consist of a narrow passageway from the surface leading to a cave cut into the chalk.

Originally used in medieval times, but also used up to the 19th century, it is believed they allowed those working the land above to mine chalk which could then be spread on fields to enrich the soil.

In 1970 in Frindsbury in Medway a huge Denehole was discovered at a chalk quarry.

Another prime example of one creating a sinkhole was at the Rainham Mark Grammar School in Gillingham, also in 2014.

Other notable sites

One of the county’s oddest attractions has long proved to the Shell Grotto in Margate.

An underground tunnel system, each wall is decorated with millions of sea shells. Its origin and purpose remains something of a mystery.

In Ashford, a small underground cell exists beneath shops in the town centre.

Believed to date back to the 15th century, the tiny jail’s history is little known.

Across the county there remain a host of former underground bunkers and command sites.

In the back garden of a property in Pluckley there is a nuclear bunker capable of protecting 12 people.

Still in good condition, a small hatch above leads down to what is effectively a cylinder buried beneath. The cramped conditions could provide shelter for up to a month.