Save these vital traces of human civilisation

It was impossible without getting a McDonald's or a high-rise block in the viewfinder. It was a graphic illustration for me of the fate of so many of the world's finest heritage sites.

Across the developing world amazing historical sites are being overtaken by development or crumbling into dust.

In China, dozens of old cities have been bulldozed. Elsewhere, heritage sites are under other kinds of pressure.

Mirador, Guatemala, is home to the world's largest pyramid, La Danta, with eight lost cities from the same Mayan era nearby.

Yet they're being looted and the forest burned: last year I drove six hours through the area without seeing a single living tree.

Elsewhere, extraordinary sites are under threat from war, natural disasters and poorly managed, unsustainable tourism: last year three million people swarmed over Cambodia's Angkor Wat temple complex.

Combined with unbridled economic development, it adds up to the biggest threat ever to these most vital traces of human civilisation.

There is a way out. In London, the Global Heritage Fund celebrated the progress of its work in China this week at Asia House.

Working with the Chinese government, we are helping safeguard ancient Pingyao, China's finest surviving walled city. But we don't want it to be a theme park: this is a living city.

So as well as restoring old Qing dynasty courtyards, we are bringing back master artisans in the old crafts - lacquering, carving, woodblock printing.

We recently completed similar work in the 800-year-old city of Lijiang. Our newest project in China is Fujian Tulou dwellings, facing tremendous challenges from neglect and development pressures.

Meanwhile in Cambodia, we are trying to save the 12th-century temple of Banteay Chhmar from looting and open it up to properly managed tourism that puts money into the local economy.

And we are working with the government and local companies in Guatemala to save the ancient Maya cities of Mirador.

But there are hundreds of sites still to be saved across the developing world. Unesco is overstretched, with more than 890 World Heritage Sites and little funding to protect those in developing countries.

The Global Heritage Fund is preparing a major summit next year to draw up an action plan and a global coalition of the private sector for saving our priceless heritage over the next decade.

We hope to multiply the available funding for the poorest countries with the most important and endangered sites.

But in the long term, the key is getting governments to see major heritage sites as billion-dollar assets - for conservation, not exploitation - because that, over a period of years, is what they are worth in well-managed tourism.

Paris gets 40 million visits a year; how many more visitors might Beijing attract if the authorities had not bulldozed most of what remains of its old city?

The world's most unique heritage sites have to be worth saving - for when they're gone, they will be gone for ever, along with their economic potential to help some of the poorest people on earth.

Jeff Morgan is executive director of the Global Heritage Fund: www.globalheritagefund.org