By Matthew Grant
BBC News, Calcutta
For decades British buildings in India were either deliberately torn down or left to decay, but now strenuous efforts are being made to preserve them.
Calcutta's Clive House was left to rot for more than 200 years
Nowhere is this more the case than in Calcutta, formerly known as the second city of the British empire.
But differences between the organisations seeking to preserve the city's heritage may hamper the work.
A ruined mansion in an area known as Dum Dum, near Calcutta's airport, still keeps the name Clive House.
But today the crumbling structure is home to 18 families of Bangladeshi immigrants.
Anal Majumdar says he has lived in Clive House for 42 years.
That is far longer than its famous owner, Lord Clive, the civil servant of the East India Company who defeated the local rulers of Calcutta in 1757 in the Battle of Plassey.
He became known to his supporters as the "conqueror of India".
His house was left to rot for more than 200 years, but restoration work has now begun.
Workers from the Archaeological Survey of India are rebuilding the structure - and soon the families will have to move out.
English Heritage is a supporter of the restoration of Clive House.
But its Indian equivalent, the Indian National Trust for Art and Cultural Heritage (Intach), is sceptical.
"In my opinion that house, if it needs to be preserved at all, should be preserved as a ruin," says GM Kapur, the convenor of Intach's West Bengal chapter.
"The British in 200 years didn't create a memorial for Clive," he said. "Why should we?"
The disagreement highlights the difficulty in restoring colonial heritage.
Bangladeshi immigrants have been living in Clive House
Besides English Heritage, other British organisations are active. The London Rivers Association has created a millennium park on the banks of the Hooghly river in Calcutta's centre.
But to some, these groups' involvement smacks of cultural colonialism.
The Calcutta Telegraph claims the British have "bagged" the river front and accuses British experts of "condescending" to locals.
What no one disputes is the destruction wrought on Calcutta's building heritage.
In many places - including Dalhousie Square, now renamed BBD Bag after the nationalist leaders Binay, Badal and Dinesh who died in the independence struggle, developers demolished old buildings and built office blocks.
New laws are supposed to protect listed buildings. But Mr Kapur says they are not foolproof.
"The builders know how to find loopholes in the law," he said. "At times buildings have vanished overnight."
The threat remains. Construction projects, including a network of flyovers, are going on all over the city.
Action Research in Conservation of Heritage (Arch) has raised awareness of the threat through walking tours of Dalhousie Square.
This helped to persuade the World Monuments Foundation (WMF) to list the square as an endangered site.
Walking tours of Dalhousie Square raise awareness of the heritage
Arch's secretary, Manish Charkraborti, is now working on an action plan to protect and rejuvenate the square.
He will present this in February to a conference of the United Nations cultural organisation, Unesco, in Calcutta.
One explanation for the damage to Calcutta's heritage is the so-called "problem of plenty".
According to this theory, the British left so many buildings, monuments and statues that it never seemed important to preserve any of them.
Yet the problem of plenty is now afflicting the conservationists. Many different organisations work in the area - and not all of them talk to each other.
Another Briton has now come forward with a solution.
Sir Rob Young was until last year Britain's high commissioner in Delhi. He is now chairman of the Calcutta Tercentenary Trust.
The trust has already restored the paintings housed in the Victoria Memorial, most of which came from the personal collection of Lord Curzon, the former Viceroy of India.
Its next project is to set up a Centre for the Built Heritage to co-ordinate the work of the many groups.
"It could be in a very fine building in Dalhousie Square called the Currency Building, which is going to be restored," Sir Rob said.
He said it could be a documentation centre, with a full set of archives for consultation. Other possible uses include training, mounting exhibitions, bringing in children for education purposes or raising local awareness.
If the conservation work is successful, many more foreigners may well come to Calcutta.
Not as conquerors seeking to make money - just as tourists looking to spend it.