Their existence is often whispered about in campus folklore. But there really are subterranean passageways meandering under many universities, their presence betrayed by a locked door, an air shaft or a seldom-trodden path.

About a mile of phoney coalmine snakes beneath Birmingham University's Edgbaston campus. The tunnel was one of the institution's earliest teaching aids. It was built in 1905 to give mining students experience of working underground. The mine is not deep and the bottom can be seen by looking down one of the mesh-covered ventilation shafts. Its entrance is inside a small red-brick building among trees to the right of the road heading north from the South Gate, not far from the Gun Barrels pub. The mine closed in the 1960s, along with the teaching of mining at Birmingham.

A series of Edwardian tunnels links buildings at the western end of University College London's campus. One connects the department of anatomy with the Rockefeller building on the opposite side of Gower Street. This twisting route is still used by staff and students. More passageways, now blocked or barred by locked doors, ran to other clinical departments in University College Hospital. Like many medical sites, the tunnels were intended to enable patients - and bodies - to be transferred between buildings in private. The 1956 film The Man Who Never Was , which told the story of a British attempt to mislead the Germans about continental invasion plans, is reputed to have been filmed in the subterranean complex.

Edinburgh University also has the buried legacy of a medical school. A tunnel was burrowed under Chambers Street when the institution was rebuilt at the end of the 18th century. It was a matter of discretion.

Bodies destined for dissection were delivered to a yard on the far side of the road, taken down stairs into the tunnel and carried out of sight to the anatomy lecture theatre.

Among the cadavers treated in this fashion was that of William Burke, the bodysnatcher who murdered people to supply unscrupulous anatomists. He was sentenced to be publicly dissected after being hanged in 1829. The tunnel survives, though it can be accessed only from a trap door in a postgraduate law lecture theatre in the Old College. It descends a flight of steps and levels into a dressed-stone passageway, but this soon ends in an abrupt wall.

Under Essex University's Colchester campus is a subterranean realm that covers about 7,000 sq m. This was formed when the institution was built in the 1960s as a series of linked squares straddling a valley. It is known to staff and students as "under the podia" and is the main service access for the university, with delivery entrances, workshops and other facilities, including car parks, amid a maze of pipes, cables and drains.

A Jacobean undercroft lies beneath Greenwich University's Queen Anne Court building, where computing, maths and business students are taught. The brick-vaulted chamber is the sole survivor of the Royal Palace, cleared to make way for what became the Royal Naval College. It was built on the order of James I as an addition to the Tudor palace in which Henry VIII, Mary I and Elizabeth I were born. The undercroft can be seen on tours organised by the Greenwich Foundation, which leases the buildings to the university.

The tunnel that once ran under the University of Kent's Canterbury campus rudely announced its presence to academics 30 years ago. It was built in 1830 for the world's first steam-powered passenger railway, the "Crab and Winkle" line that ran from Whitstable to Canterbury. The half-mile brick tunnel ran under Tyler Hill and was in use until 1952. The university was constructed over it. On July 4, 1974, the tunnel began to collapse.

Hairline cracks were seen in the northwest corner of the new Cornwallis building. A week later, the structure sank a metre in an hour. Engineers demolished the building and filled the length of tunnel with concrete. One of the few remaining traces of the line close to the university is a brick culvert for the Sarre Penn stream just to its north.

At Roehampton University in South-West London, a once ornate neo-Gothic tunnel still cuts under Roehampton Lane. It linked the grounds of Elm Grove, a mansion built by financier Benjamin Goldsmid in 1797, with pleasure gardens and a farm. The house was praised by Sir Richard Philipps for its uninterrupted view of the country towards Harrow. But the writer reserved most enthusiasm for the tunnel: "The object which most particularly called to mind the unbounded wealth of the former proprietor is a subterraneous way to the lawns... finished with gates resembling those of a fortified castle with recesses and various ornaments." The crenellated eastern entrance, with its Portland stone arch, was demolished in 1957 when the road was widened. The western entrance is a much rougher affair, but the tunnel is still passable.