THE clean-up of once coal-blackened North-East beaches will be highlighted in an exhibition revealing some of Britain's hidden coastal gems.

Before and after pictures of a stretch of shoreline at Horden, County Durham, feature in the long-running display, which opens at the National Maritime Museum, in London, on Wednesday.

The beach at Horden was one of many on the County Durham coast transformed by the £10m Turning the Tide project, following the demise of the coal industry.

Previously the coast was blighted by decades of colliery waste being dumped at sea, which led to spoil being washed back up on the beaches, in some cases creating a lunar-type landscape.

As part of the five-year project, which ended in the spring of 2002, some of the coastal stretches were developed as sites of special scientific interest, encouraging wildlife to thrive.

Among them was Horden, where there are signs of flora and fauna starting to return.

Local National Trust officer Dennis Frazer said a lot of effort was still being made to encourage the return of the coastline to its natural state.

He said: "We have already seen huge signs of recovery up and down the coast.

"Although there has not been an increase in the number of different species, there has been a rise in the number of animals within each species."

He said limpets, mussels and common seaweed were starting to flourish in some rock pools.

He said: "It's a sign that the waters and the beaches are becoming cleaner."

The exhibition, The Coast Exposed, is at the museum, in Greenwich, until January.