site unseen Camley Street Natural Park, King's Cross, London

Some parts of London never appear in visitors' guidebooks. This is fine if you like tourist-free zones, but it does mean that the "official" view of London is decidedly sanitised.

Take the area to the north of St Pancras and King's Cross railway stations. If you say that you actually enjoy walking around this neighbourhood, then most people promptly write you off as a drug addict or a prostitute. But there is as much to relish here as in more high-profile and glamorous parts of London.

Just look at the mid-Victorian tenements in Stanley and Clarence Passages off Pancras Road which played a starring role in Mike Leigh's fine London film, High Hopes. Or the gasholders of 1860 with their interlacing tracery which still stand proud and erect further to the north. Glance back at the engine shed of St Pancras and the sweep of the single-span roof still takes the breath away.

Marvel at the stunning example of industrial architecture which is the granary of 1850, designed by Lewis Cubitt, the architect also responsible for the austere frontage of King's Cross station until it was spoilt by later additions. Delight too in the pretty stretch of canal nearby with its fine views, colourful narrowboats and stables for the horses, who actually shifted the barges on their way down to the Thames.

And as you walk down the canal, just behind the lock-keeper's cottage, you will glimpse an intriguing green oasis. Find your way back onto Goods Way and then approach from the front. Here, tucked well away and nearly out of sight, is one of London's great survivors, Camley Street Natural Park.

Born just over 10 years ago on scrubby wasteland which had once contained the coal drops for the nearby goods yard, the park's two-and-a-half acres have now matured. They provide a striking reminder of what London was like, when, 1,000 years ago, the unruly Forest of Middlesex began to be tamed and turned into farms and market gardens.

The park contains a pond, a small marsh, a wild flower meadow and an immense variety of animals and plants. It is run by the splendid London Wildlife Trust, which does its best all over the capital to beat back the periodic assaults of Mammon whenever councils and property developers suddenly spy a killing.

However, the threat to its continued existence has abated but not disappeared. From time to time, plans are drawn up which invariably call for the commercial transformation of this area and the extinction of the Natural Park. If your best friend is a developer, then don't tell him about this rural retreat. Careless talk can cost open spaces.

Camley St Natural Park, off Goods Way, London NW1. Open to the public every day except Fri