Why are we asking this now?
A United Nations team is about to visit Bath to decide whether the city still deserves the accolade of a World Heritage Site. There are 28 such sites in Britain but Bath is the only entire city to be listed.
But the heritage police are worried. They originally called Bath "a city that is harmonious and logical, in concord with its natural environment and extremely beautiful". But now they fear this might be spoiled by a new development to which the city council's planning committee has given outline permission. It will add 2,200 houses with shops, a school and a park right next to the River Avon. Some of the buildings are nine storeys high.
Enthusiasts for the scheme attack those who would keep Bath as "a city in aspic" and worry that the whole project may be at risk if the United Nations Educational, Scientific and Cultural Organisation (Unesco), which grants world heritage status, disapproves.
What kind of places are given the accolade?
Anything from a city to an individual building, monument, area, forest, mountain, desert or lake. There are currently 878 world heritage sites which include 678 listed for cultural reasons and 174 lauded as wonders of nature. These include the Great Barrier Reef, the Serengeti Desert, the Pyramids of Giza, the Statue of Liberty, the Great Wall of China, Mount Kenya, Edinburgh's Old and New Towns, Hadrian's Wall, Stonehenge, Memphis and its Necropolis, Persepolis, the Palace of Westminster, the centre of St Petersburg, the Banaue rice terraces in the Philippines and the Chhatrapati Shivaji Terminus railway station in Mumbai. The country with the biggest number of sites is Italy, which has 43.
How did the idea begin?
In 1954, the desert valley containing the twin Abu Simbel temples – which were carved out of a mountainside in southern Egypt in the 13th century BC on the orders of the Pharaoh Ramesses II – were about to be flooded by the building of the Aswan Dam. Frustrated by the Egyptian government's lack of action to protect the ancient buildings, Unesco launched a worldwide campaign that saved the temples by relocating them to higher ground at a cost of $80m, half of it collected from 50 countries.
The project was such a success that Unesco campaigns followed to save Venice and the ruins of one of the world's earliest urban settlements, Mohenjo-daro in Pakistan's Indus Valley, as well as the largest Buddhist structure in existence, the Borobodur temple compounds in Java, Indonesia.
Who decides whether heritage status is granted?
The Unesco World Heritage Committee, which is elected by nation states every four years. It meets once a year to choose the world's natural or human-made wonders in the greatest need of protection. Any country is eligible to send in a list of nominees for protection.
This year, the committee met in Quebec City, Canada, and added an extra 27 places across the globe to its list of "endangered species". Among them were more than 100 monumental tombs at Al-Hijr in Saudi Arabia, built by the Nabataean people between the first century BC and AD100. Another was the Monarch Butterfly Biosphere Reserve in Mexico, where one billion butterflies overwinter each year. The committee also added the island of Surtsey, which appeared 20 miles south of Iceland as a result of volcanic eruptions between 1963 and 1967, and is a pristine natural laboratory for the study of plant and animal colonisation.
What are the criteria for inclusion in the list?
Each site must meet at least one of 10 criteria. They must represent a "masterpiece of human creative genius", be "an important interchange of human values" or "bear a unique or at least exceptional testimony to a cultural tradition or to civilisation" past or present. Or they can be an outstanding example of a type of building or settlement which illustrates a significant stage in human history. They can "contain superlative natural phenomena or areas of exceptional natural beauty and aesthetic importance", or be outstanding examples of major stages of Earth's history or ecological and biological processes in evolution. Sites can also house threatened species "of outstanding universal value".
How political isthe choice?
Well, just nine per cent of the world heritage sites are in Africa and seven per cent in Arab countries, compared with 50 per cent in Europe and North America. This does suggest a certain cultural bias, but there are other political considerations. The US, whose government saw Unesco as a stalking horse for Communist and Third World countries to attack the West throughout the 1980s and 1990s, has refused to propose any new heritage sites since 1995. In that year, plans to open a gold mine near Yellowstone Park in Wyoming got the area placed on Unesco's "world heritage in danger" list. Conservatives in Washington decided that the scheme was an undercover attempt to subvert America's rights to govern itself and to destroy the fabric of US sovereignty.
Have there been any other controversies surrounding the scheme?
Pressure groups use world heritage status as a lever in political battles. In Australia, a group of Aborigines teamed up with environmentalists in a dispute over a uranium mine in the middle of the Kakadu National Park, a World Heritage Site which is home to hundreds of species of wildlife and is one of the country's oldest places of human occupation, dating back 60,000 years. Unesco called on ministers in Canberra to put a stop to the mining project, but the government hit backing, saying Unesco's report contained errors of fact, law, science and logic.
There was a similar row over a controversial hydroelectric dam project in La Amistad International Park, a world heritage-designated site which straddles Panama and Costa Rica and is Central America's largest and most diverse virgin rainforest.
What are the benefits?
Listed places receive extra media attention and tourists. That brings extra money in addition to cash from Unesco's preservation fund, though only developing countries can apply for the grants. Britain contributes £130,000 to the fund every year but gets nothing back, although world heritage status can attract extra funding from the national lottery and the private sector.
Publicity can help. Two 150ft statues of Buddha carved into a mountain in the Bamiyan Valley in Afghanistan in the 6th century, and which were destroyed by the Taliban in 2001, have received more than $4m from Unesco to help with the re-sculpting of the damaged stones.
And the disadvantages?
Listed places receive extra media attention and tourists. The higher profile that listing brings can draw an influx of visitors that poorer countries cannot handle. Fore example, the Angkor Wat temples in Cambodia, the Galapagos Islands and Machu Picchu in Peru have all seen massive increases in tourism. Sometimes listing does more harm than good and upsets the delicate balance between promoting places and preserving them.
Does it help to have World Heritage status?
* It brings extra funds to poor countries to help conserve places of universal value
* It draws attention to the world's most neglected treasures and places of historic interest or natural beauty
* It can save places from total destruction by natural or human forces
* It brings in floods of extra tourists whose footprint can do more harm than good
* It can have the effect of preserving a living place in aspic and stifling innovation
* It can undermine a country's right to make decisions about its own heritage