THE SUNDAY WALK: An army of spectres haunts the labyrinthine heart of the old City of London, but you need a spirit guide to introduce them to you
This was supposed to be a Charles Dickens walk, but after waiting for half an hour in the cold with three German tourists at the appointed place outside St Paul's Tube station, an old woman wrapped up like a Chechen in winter whispered to me that at 7.30 there would be a Ghost Walk from the same place.

A ghost walk? The Germans promptly left in disgust, but were soon replaced by a large and boisterous group of young Londoners with an improbable interest in the supernatural. They would not be disappointed. In the next hour-and-a-half our guide recounted around 20 ghost stories.

The route twisted and turned but, nevertheless, key landmarks stood out. From the Tube station (cathedral exit) we took the dark steps to the immediate left and walked west among ugly offices between the station and St Paul's Cathedral (which has its own ghost) in the direction of Ave Maria Lane.

West off here is Amen Corner, a tiny lane which contains 500-year-old houses and the surviving rear wall of Newgate Prison, which also has a ghost, one Jack Shepherd, a burglar.

A minute south of here, across Ludgate Hill Road and slightly to the east, is Deans Court. South down here, at the junction with Carter Lane, we passed the 1930s AA Restaurant, which has a preservation order on its original cut-glass windows. No ghost though.

The streets south of Carter Lane are particularly narrow and confusing, but if you dig around you'll find such curiosities as the Church of St Andrew's-by-the-Wardrobe, and, on Blackfriars Lane, a tiny heap of stone (marked by a plaque) which is all that remains of the original Blackfriars Monastery, torn down by Henry VIII. Brother Gervais, a dead monk, can be seen here on windswept nights.

At the northern end of Blackfriars Lane, we walked left (west) a few metres along Pilgrim Street and were able to see, ahead and across the main street, the tiered spire of Wren's Church of St Bride's, the inspiration for generations of wedding-cake makers.

Avoiding Fleet Street to the west (where Sweeney Todd cut hair and throats) we walked north, back across Ludgate Hill and up Old Bailey to the Central Criminal Court. In the early 19th century you could buy all-inclusive execution holiday breaks for pounds 10 which included bed and breakfast in the Magpie and Stump opposite; there were fine views of the hangings. Among the many Old Bailey ghosts is one Mrs Dire, a notorious "baby farmer". Trials today can be viewed (free) on weekdays from 10.30am to 1pm and 2.30 to 4pm.

Continuing north, we entered Giltspur Street, where a watch-tower squats on the left, designed to guard a graveyard against body-snatching medical students from St Bartholomew's Hospital. Immediately afterwards, Cock Lane is, perhaps inevitably, haunted by a ghost named Fanny.

We followed the wall of St Barts north-east to the historic main entrance (on West Smithfield), crowned by the only outdoor statue of Henry VIII in London. Near by is a plaque marking the spot where Scottish patriot William Wallace was executed in 1305. Flowers are still placed here.

At the end of the road, across Little Britain, a tiny entrance leads to the brick-built Church of St Bartholomew the Great. Navigating a few lanes north of here brings you out on Long Lane, opposite the magnificent Smithfield meat market - look out for the 24-hour cafe Smithfield's if you are here at night. We walked north up Lindsay Street on to Charterhouse Street, notable for the Fox and Anchor pub which opens at 7am and offers some of the best fried breakfasts in London. In Charterhouse Square, just to the east, a chilling 35,000 ghosts of plague victims are said to wander. They were, apparently, buried in the square.

We headed back south and soon saw the floodlit dome of St Paul's again. Our last ghost at the corner of King Edward Street and Newgate, was in Greyfriars Passage by the bombed church. A shadow on the wall, or a drunken city gent? I looked round but our guide had gone.

This was one of many tours by The Original London Walks, and costs pounds 4.50/pounds 3.50. Tel: 0171 624 3978.