But before long, if Tony Blair has his way, the same govern- ment will have drowned it for ever beneath the deep waters of a reservoir. And instead of being remembered as a cradle of civilisation, its chief claim to fame may turn out to be that it was at the heart of the first of the water wars that are expected to plague the planet in the coming century.
Mr Blair is insisting, despite doubts and outright opposition from some senior ministers, that Britain should provide financial backing to enable the construction of a dam that will submerge the town. This, in turn, will make it possible for Turkey to threaten to cut off the waters of the river Tigris from Syria and Iraq.
Hasankeyf, in the south-east corner of Turkey, is the only town in the region to have survived from the Middle Ages. Some historians believe that people settled there 10,000 years ago, not long after the birth of agriculture.
But the ancient town is only one of the expected casualties of the planned Ilisu Dam, which a consortium of companies, headed by the British giant construction firm, Balfour Beatty, wants to build. Some 52 villages and 15 towns would be submerged by it, and driving some 20,000 people from their homes.
And it is only one of a chain of 22 major dams, 19 hydro-electric plants, and dozens of irrigation schemes planned for completion in this part of Turkey by 2010. Already hundreds of thousands of people have been driven from their homes, many without compensation. The massive scheme is being implemented in the heart of one of the region's most potent flashpoints, the theatre of a civil war between the country's Kurdish minority and the Turkish army.
The Turkish government sees the dams as serving a political purpose, as well as providing irrigation for agriculture and electricity for a country in which demand for power is doubling every nine years. It is hoped that by flooding their homes, it will be able to move the Kurds off their traditional lands and house them in towns where they can be more easily controlled. The Kurds, for their part, see it as just another attack on them.
But the strategic implications of the massive scheme are likely to spread far beyond Turkey's frontiers, and the proposed Ilisu Dam is expected to play a central part. For it would be just 40 miles from the borders with Iraq and Syria, and the Turkish government would be able to stop fresh water flowing into the two countries by closing the sluices.
"The next war in the Middle East will be fought over water, not politics," said Boutros Boutros-Ghali, when he was secretary-general of the UN. The CIA agrees. In 1992 it identified the struggle for water between Turkey and Syria as the most likely cause of war in the region.
There have already been crises. In 1989, Turkey threatened to cut the flow of the river Euphrates into Syria because it was supporting the Kurdish dissidents. The next year it did stop its flow altogether, so as to fill a dam: the Iraqi and Syrian media denounced the move and there were threats of retaliation.
Suleyman Demirel, President of Turkey, has said: "Neither Syria nor Iraq can lay claim to Turkey's rivers any more than Ankara can claim their oil. We have a right to do what we like."
Water wars are likely to spread all over the world in the next century. Today 26 nations are already short of water: by 2020, some 66 are expected to be. Soon afterwards, the UN environment programme estimates two out of every three people will live in regions without enough water. The Nile, Zambesi and Mekong are all potential flashpoints.
"The [British] Government could not have had the dangers of this project spelled out more clearly," says Tony Juniper, policy director of Friends of the Earth. "If the Prime Minister is not careful, the Ilisu Dam could finish up tarnishing this government's reputation even more than the scandal over the Pergau Dam did for the Conservatives."
The Pergau scandal, in which aid money illegally financed the dam as part of an arms deal with Malaysia, was also a product of prime ministerial det- ermination: Margaret Thatcher pushed the plan through.
The Ilisu affair will also shine a spotlight on export credit guarantees, under which the Government agrees to under- write projects taken up by its industry abroad, and pay if the host country fails to. The unpaid money is added to the country's debt. Old export credit guarantees make up the largest part of the debt burden owed by Third World countries to Britain.
The system is being reviewed. Until now, sources say, the merits of whether or not to grant a guarantee can only be judged in financial terms. But last month Stephen Byers, the Trade Secretary, said environmental factors must be taken into account. However the Ilisu affair turns out, it is bound to increase pressure for reform.