PEOPLE could mistakenly believe they have been transported to a different time dimension if they stumble across a Doctor Who Tardis.

In fact, there are 237 blue police call boxes (PCBs), on which the BBC modelled the fictional time lord's transporter.

And one of them is in Almondbury.

It's now disused, but still in police hands.

The Northgate box became a listed building in 1987 - at that time it was thought to be the only one to get the distinction.

Ordnance Survey has tracked down the locations of all former PCBs using a digital master map of Britain - technology which may well have delighted the creators of the sci-fi classic.

The exercise was carried out as the nation prepares for the eagerly-awaited revival of Dr Who on TV tonight.

Christopher Eccleston and assistant Billie Piper burst on to the screens at 7pm on BBC1.

Almondbury's police box is thought to be the last in West Yorkshire.

Although out of use, the police give it a nice coat of paint once in a while.

Other Dr Who boxes dotted around the country can now be found disguised as coffee kiosks.

Personal radios made the police kiosks redundant as phone boxes in 1969.

Many of the boxes were topped by electric lights.

They contained a telephone linked directly to the local sub-divisional police station.

Officers on beat patrol could report their whereabouts.

The flashing light indicated whenever the station wanted them to make contact.

The public also had access to the boxes to enable them to contact police quickly.

When the BBC started producing Doctor Who in 1963, the police box was adopted as the ideal vehicle for the charismatic time lord.

The Tardis - Time And Relative Dimension In Space - was many times larger on the inside than it appeared from the outside.

Just as the television show is being resurrected, police are experimenting with bringing the boxes back, although now they are more hi-tech.

In London, a police box was installed at Earls Court in April 1996.

It was equipped with closed circuit TV, digital imaging equipment and a public telephone linked directly to the police switchboard.

DR WHO FACTS

* First aired on November 23, 1963 with William Hartnell in the title role.

* BBC props people once made a monster for the programme out of noodles covered in washing-up liquid.

* Tom Baker's first Dr Who scarf was 13.5ft long. By the end, he had one that stretched to 24ft.