Site Unseen: The Panels on The Monument, London EC3

The recent re-opening of the Monument in the heart of the City of London means that anyone unable to afford the sub for an expensive health club can now come here for exercise. Its 311 steps will test the lungs to bursting point but the prospect from the top is breathtaking.

Nearby is Pudding Lane, boringly modern but with a plaque erected by the Company of Bakers in 1986 apologising for the negligence of a former member, Thomas Farrinor. It was in Farrinor's house that the Great Fire of London started in the early hours of Sunday, 2 September 1666 when an oven was not properly extinguished.

Guides will tell you that if the Monument, erected in the 1670s, was pushed over then the flaming golden urn on top would land on the site of Farrinor's bakery. Not so. The Monument is 202 feet high but the fire began 140 feet away.

Does this mix of myth and fact matter? Yes. The outbreak of the Great Fire was due to negligence or, as the official inquiry put it, "the hand of God, a great wind and a very dry season." But the scaremongers were not happy with this and instead blamed the Catholics. Until 1830 an inscription on the north panel blamed "the treachery and malice of the Papists".

An alternative explanation was advanced by a preacher who noted that the fire had begun in Pudding Lane and ended in Pie Corner. So gluttony was to blame - an early PR job for Weightwatchers.

Pedestrians should ignore this speculation and scrutinise the pedestal of the Monument. Three sides carry dull Latin inscriptions, but the fourth is graced with a superb piece of sculpture by Caius Cibber which shows Charles II, dressed in fancy Roman costume, supervising the rebuilding of London.

The king commands Father Time to lift up the bedraggled and very feminine figure of the City. Another bare-breasted beauty (the influence of Charles II?) points up to the heavens, where Peace and Plenty look on happy and content. In the top left corner, smoke pours out of burning buildings. In the top right, scaffolding supports brickies as they rebuild the capital.

But my favourite detail is tucked away in the bottom right-hand corner. Charles and his brother the Duke of York are standing on the hideously deformed figure of Envy, who is suffering from a particularly severe case of halitosis. Remember to clean your teeth before climbing.

The West Panel, The Monument, Fish Street Hill, London EC3