Calcutta's skyline has been transformed

That is a familiar story and as yet there is no city law that can stop what environmentalists in Calcutta call vandalism by big business.

Of course it is not a problem unique to Calcutta. You only have to look around London to see the results of planning and development failures 30 or 40 years ago.

But today, in Calcutta, there is such a lot at stake.

Despite sporadic periods of re-development this city is still peppered with superb buildings that date from the time of the East India Company - huge classical piles lined with fluted columns topped by Corinthian and Ionic capitals.

St Thomas's Church, one of the colonial style buildings

There are libraries, government offices, museums, churches and even the central post office looks like a temple.

British military engineers with pattern books full of Greek temples and Roman triumphal arches designed them all.

St John's Church, just along the road from Government House was built in the mid-18th entury and still has its original teak pews, along with portraits of several archbishops of Canterbury in the vestry.

The oldest British resident in Bengal

In the overgrown churchyard there are memorials to those who died in the Black Hole of Calcutta and to Job Charnok, the founder of Calcutta in 1690.

The gravestones are a reminder that in the 18th century a young English merchant or soldier working for the East India Company had the life expectancy of a fighter pilot during the Battle of Britain.

But women seemed to fare better and there is one memorial to Frances Johnston whose husbands are listed in stone - I counted all seven of them.

As they were carrried off with cholera or malaria she kept on marrying and in 1812 at the age of 87 was feted as the oldest British resident in Bengal.

Government House is stunning. It is a copy of Kedleston Hall in Derbyshire - a huge mansion decorated with rows of pillars, pediments and statuary. The front and the back of this Robert Adam look-a-like stately home, feature semi-circular rooms topped by large domes.

No expense spared

When the Governor General of the East India Company in Calcutta sent the plans to head office in London in the late 18th century they turned them down because of the expense.

But by the time it took for the letter to reach Calcutta, the mansion had been built.

In the classical style - the State building, Calcutta

Of course, there is no question of this building being turned into a car park - the governor of West Bengal lives there today in similar style to the last British viceroy.

Indeed the governor still uses the electric lift that Lord Curzon installed at the end of the 19th century.

But the danger to other buildings, I am told, comes not just from commercial developers but also from a turf war between central government departments run from Delhi and the Calcutta Municipal Corporation.

Ignoring local protests central government has knocked down historic buildings it owns and replaced them with high rise concrete and glass.

Calcutta is a city full of crumbling wonderful buildings that are ripe either for redevelopment or restoration and the Calcuttans have chosen the latter.

The architecturally stunning High Court

Over the past five years several pressure groups have won court orders to halt development projects and a list of heritage sites now being drawn up already numbers 1,000 buildings that are of historic and architectural interest.

But the legislation that would give them legal protection has not yet reached the statute book.

Nevertheless scaffolding has begun to appear on buildings that have not seen a coat of paint or a down pipe cleared for half a century.

One such building, the Metcalfe Hall, built in 1838 and designed to be a copy of the Temple of the Winds in Athens, has just been restored.

Clive of India's country house is slowly mouldering away into an ivy-clad ruin

It started life as an imperial library but it had been abandoned in the 1960s and boarded up. The roof was leaking and rubbish had piled up against its impressive colonnade of fluted columns.

Now it is safe and designated as a national monument - one of the few protected buildings in the city.

But Clive of India's country house just outside Calcutta is in a sorry state. It is a huge brick mansion on high ground about 10 miles from the city centre. Built just after the Battle of Plassey in 1757, its roof has fallen in and it is slowly mouldering away into an ivy-clad ruin.

It does not appear on any maps and it is only in the last couple of years that official India has shown any interest. Architectural conservators, however, believe that it could still be saved.

It is true to say that a start has been made to save Calcutta's unique architectural heritage, and people are taking part in clean-up campaigns in the city. Mountains of rubbish have been moved and a stretch of the riverbank has been reclaimed from dereliction and opened up as a millennium park.

Calcutta streets have been cleaned up

Streets in the city centre are now being cleaned every morning and the image of Mother Teresa's poverty-stricken chaos is dimming, with the hope that more than the present trickle of tourists might come.

A measure of the city's growing confidence and determination to maintain its colonial heritage is the new policy of the communist city authorities towards the statues of the Raj.

After independence in 1947 they were unceremoniously taken down and dumped in a store.

Now the sculpted marquises, viceroys and generals are to be allowed out again in public, and environmentalists are pressing for them to be returned to their original plinths still in place throughout the former imperial city.