The sites on the list range from the ancient, such as Machu Picchu in Peru and desert castles in Uzbekistan, to the comparatively modern, such as the Merritt Parkway in the US state of Connecticut.

Sites 'irreplaceable'

Those sites selected for the WMF are considered by the organisation to be "irreplaceable monuments to human culture".

"They are found in every type of environment, from urban centres and small towns to barren plains and riverside caves, and they are threatened by war, natural disasters, urban sprawl, and neglect," the organisation's report said.

The WMF said that while not all sites on its list for 2010 are considered to be in imminent danger, careful planning would help avert crises in the future.

But the organisation pointed to several cases where heritage sites were either being destroyed or at immediate risk of damage.

The report highlighted the decision by the authorities in the Japanese city of Kyoto to tear down traditional townhouses called machiya.

Some of those houses date back to the early 1600s, but are now being destroyed to make way for more dense buildings.

The WMF also said that the foundations of Antoni Gaudi's Temple Expiatori de la Sagrada Família in Barcelona, Spain, could be compromised by a new underground train line.

While the WMF said that it was important that the authorities in charge of heritage sites should encourage tourism, they should also take steps to ensure that visitors do not harm fragile monuments.

The organisation pointed to Taos Pueblo in New Mexico as an example where residents and the local authorities play a leading role in preserving the site.