By Jane Elliott
Health reporter, BBC News
King's Cross is one of London's busiest areas with its huge station, traffic-clogged streets and active nightlife.
Nick Black hopes to preserve the capital's medical history
But how many people passing through the area pause to take stock of its history - or indeed that of much of the city?
Would they know the area was once home to both the London Smallpox Hospital and the London Fever Hospital, which were bulldozed in 1848 to make way for the Great Northern Hotel?
Now Nick Black, professor of health services research at the London School of Hygiene and Tropical Medicine, is urging people to take time out to rediscover not only this area, but a large part of the capital's medical history.
He has written a book detailing seven walks to existing and long-gone medical sites.
His aims are to understand how the capital's health service developed the way it did and to help preserve a knowledge of its history.
Professor Black said the book, written and researched over three years, had been a joy to write.
"The more I dug around the more I discovered," he said.
In the book, Walking London's Medical History, Professor Black explains how events such as the Napoleonic wars were the catalysts for hospital services developing.
For instance, before 1800 eye diseases were mainly dealt with by unlicensed occultists, with the only specialist hospital - St John's Hospital for Diseases of the Eyes, Legs and Breasts in Holborn - closing two years after its opening in 1771.
However, all this changed when many soldiers returned in 1803 from their campaigns against Napoleon in Egypt with serious eye infections.
This spurred the opening of three eye hospital - the Royal Infirmary for Diseases of the Eye, in Cork Street, in 1804, the London Dispensary for Curing Diseases of the Eye and Ear, in Charterhouse Square, in 1805 and, in 1816. the Infirmary for Diseases of the Eye, in St Giles.
The book also chronicles the history of the Fistula Infirmary, originally sited in Aldersgate Street, in 1835, where Lord Mayor of London William Copeland and Charles Dickens were treated for anal fistulas - a complication from an abscess.
By 1853 the infirmary had moved to City Road, where one of those to benefit from treatment was Jack the Ripper suspect, artist Walter Sickert.
"His treatment has been used as evidence that he suffered from an anal fistula and not, as those who believe he was Jack the Ripper have alleged, a penile fistula - which would have rendered him impotent and therefore, they claim, more likely to be a serial killer of women," said Professor Black.
He added: "Each walk helps to preserve London's heritage as former health care buildings are increasingly converted into hotels, offices, homes and shops with public knowledge of their original function in danger of being lost."
His personal favourite is around the Soho area of the city - home to the city's first hospital for women, the first ear, nose and throat hospital (the Royal Ear Hospital) and the first and most famous anatomy school (Great Windmill Street School).
He said this area, which has always been home to London's foreign population, suffered little bomb damage during WWII and, as a result, the street patterns have remained virtually unchanged for three centuries.
"It has always been quite bizarre. When you get there it is like a different world and historically it has always been a place for foreigners."
He said this area had a strong part to play in the city's sexual history.
"Soho is somewhere to take risks, to challenge orthodoxy."
He said the consequences of this sexual liberalism were evident in its history - as it was home to London's only specialist hospital for men with venereal disease, the London Lock Hospital, and the Hopital et Dispensaire Français, which offered medical services to prostitutes.
There were also three hospitals in the area that openly offered treatment for venereal disease.
Author Peter Ackroyd, who has written the book's foreword, says it chronicles London's medical past from a time when it was so dirty and unhealthy that it was once known as a "vast hospital", to the present day.
"The stories told along the route of this pilgrimage are of intense interest, reflecting as they do the continual battle against sickness and disease that engaged generation after generation of Londoners."
The book, costing £14.95, is published by the Royal Society of Medicine Press.