Nose round a Victorian Londoner's home, get locked in prison cells or stand in a Spanish garden seven storeys above ground... Join our writer on her tour of a London that tourists rarely get to see.

I had guests coming to stay for a weekend, and I decided to give them a taster of the true flavour of London - the one that city-breakers seldom sample. 

What better way to show how life is really like in London than to get inside a Londoner's home? So we headed to High Street Kensington, where, not far from the bustling shops, we stepped back in time. Anonymous and unmarked in a street of imposing five-storey Victorian townhouses, Linley Sambourne's House (website: www.rbkc.gov.uk/linleysambournehouse/general/default.asp) would be impossible to spot for those who did not know its location.

At weekends, costumed actors provide intimate tours of this almost entirely preserved former home of the Victorian Punch cartoonist. The front door was opened by the ‘Sambourne's housekeeper' and she quickly ushered us in, concerned that, ‘the neighbours might gossip'. And so began a fascinating insight into life in London for a household during a defining era for the city.

The housekeeper remarked that Mr Sambourne had quite a sense of humour and showed us a stuffed bird in a framed glass dome by the front door and on the opposite wall, behind where the door would swing back, was framed a flattened bird. Every wall in the house was covered with pictures, and we were shown some gaps in the wallpapering, revealed thanks to Mr Sambourne's restless repositioning; the Sambournes, it seems, were also quite frugal.

Emerging back out into the 21st century, eyes blinking, we felt almost disorientated. As we walked back along Kensington High Street, we passed the art deco department store that was once Derry & Toms, and I remembered The Roof Gardens (website: www.roofgardens.com) that flourish atop it. First-time visitors are always startled when they leave the lift on the seventh floor and step out onto a lawn, with fully-established trees, shrubs and flowers. In the 0.6 hectares (1.5 acres) of gardens, my guests laughed with joy as they came across the mock Spanish convent, wandered English woodland and then spotted pink flamingos loafing in a shady pool.

Later that evening, I opted for a restaurant that is a delightful surprise in an unlikely spot between the newsagents, greasy spoons and second-hand furniture shops of Clapham Junction's Falcon Road. Fish in a Tie (105 Falcon Road; tel: (020) 7924 1913) is easily missed - emerging from the dark undercarriage of Clapham Junction's rumbling and dripping railway bridges, we nearly walked straight past, as scaffolding obscured its bright purple exterior and hand-painted eponym.

Stepping inside, we were enveloped by warmth, a wood-panelled bar, Venetian glass mirrors, trickling candles in bottles... and dozens of people - we felt reassured. Trendy ‘Claphamites' were packed into every corner. A smiling waitress led us to a table right at the back of the restaurant, in a cave-like annexe with white-washed walls, enormous heavy-framed paintings and multicoloured Tiffany chandeliers.

Squeezing into reclaimed church chairs, we excitedly perused the well-priced menu. We were spoilt for choice with much more than just fish dishes, but my mind was quickly made up with the day's specials. For starter, cool caviar with sour cream and avocado, followed by a red snapper main. The juicy white fish in a Puttanesca sauce was complemented with melt-in-the-mouth seasoned boiled potatoes cut like chunky chips and crunchy garlic green beans. Enjoying the atmosphere so much, we prolonged our stay with desserts of light and airy almond cake and creamy banoffee pie.

The next day, I led my guests into the intriguing Postman's Park (between King Edward Street, Little Britain and Angel Street), not far from St Paul's Cathedral. Although this small green oasis is well-known by city workers who eat their sandwiches here on summer's days, few tourists would stumble across it. Few also know that this was an integral location in the 2004 film Closer. The wall of plaques remembering ‘forgotten' heroes of the 1800s to early 1900s is moving to read, and produced a clever storyline in the film. The plaques commemorate ordinary and courageous people in such incidents as rescuing their co-workers or relatives from fire or from drowning, at the cost of their own lives.

A short wander down from St Paul's, more unhappy stories of Londoners were revealed to us when we stopped for refreshment in The Viaduct Tavern (126 Newgate Street; tel: (020) 7600 1863). A typical old London pub, with red embossed wallpaper, copper-topped tables, and plenty of dark wood and etched glass, this was once a gin palace. Downstairs, however, reveals a different world. We requested, as the blackboards in the pub urge, to be shown the ‘cells'. The manager led us down rickety wooden steps and we were soon in the cold and damp underground.

Through the cellars and storerooms, we came to one of the remaining cells of Newgate Prison, where we were told up to 20 prisoners would have been crammed into this space measuring no more than an average garden shed, with the only daylight supplied by a narrow tube going up through the concrete to the street above, also used by sympathetic relatives to drop food down.

As we huddled in this eerie space, the manager explained there would have been no toilet facilities, quickly giving us an idea of how bad the stench would have been. She showed us another even darker cell that was filled with what looked like metal storage cages. ‘What are those?' I asked. ‘Well that's how they managed to fit so many prisoners in here' the manager replied, grimacing. The cage-like constructions left the inmates with no room even to sit up straight or stretch out their legs. And what were the horrendous crimes these convicts had committed? They were merely debtors. 

We scurried out of the Viaduct in sombre moods, until one of my visitors suggested, ‘Fancy a stroll round Trafalgar Square?' and we eagerly agreed. Some parts of London, it seems, are best left as secrets.

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