Devon and Dorset attract dedicated fossil hunters
The honour for a 95-mile (150 kilometres) stretch of shore in Devon and Dorset has been granted by Unesco, the United Nations' cultural committee.
It is the first site recognising natural heritage on the British mainland - joining the Giant's Causeway in Northern Ireland and the Scottish island of St Kilda.
The declaration covers the area between Exmouth, east Devon, and Dorset's Old Harry Rocks, near Swanage - passing through nine internationally significant sites.
Unesco declared it "an outstanding example, representing a major stage of earth's history and the record of life".
It yields a steady flow of dinosaur remains, including previously-unknown species.
National treasure
Dorset county councillor Hilary Cox said: "We hope the government and other agencies will now give the Jurassic Coast the financial support it deserves.
"Our coast is a national treasure, which has now been recognised as globally important."
Devon county councillor David Morrish said: "The coast provides a unique walk through time with an amazing wealth of fossil sites and landforms.
"Those who know the area recognise not only its scientific importance but also the beauty of the inspiring coastline."
Dinosaur footprints are found among the spectacular limestone coves and headlands of Purbeck and the Isle of Portland.
Devon's red sandstone cliffs include important Triassic sites at Ladram Bay and Sidmouth.
Global fame
On the imposing cliffs of the Devon-Dorset border, around Lyme Regis and Charmouth, several layers of geological history are clearly visible.
It was in the area around Charmouth and Lyme Regis that palaeontology, the science of fossils, first attracted popular interest.
The indomitable Mary Anning drew global fame when she found the first remains of the Ichthyosaurus species, a giant marine reptile, and the first known pterodactyl, a flying reptile.
In 1999, a previously unknown ichthyosaur was discovered near Lyme Regis by local fossil hunter Chris Moore.
Spectacular landslips in east Devon have opened up thickly-wooded chasms.
One, at Lyme Regis, was made famous as the Undercliff in the John Fowles novel, The French Lieutenant's Woman.
Tourist boom
Dorset and Devon county councils spent seven years on their bid for World Heritage Status.
They hope the honour will bring tourism and other benefits to the area.
Bids are also under way for other UK sites to be similarly recognised in future years, including the former tin mining areas of Cornwall and the coast of Pembrokeshire.
The committee was also considering three other British sites this week: the textile settlements of Saltaire, in Yorkshire; New Lanark, in Scotland and Derbyshire's Derwent Valley.