Heritage body which already looks after five miles of the Kent cliffs needs to raise £1.2m to buy one-mile stretch up for sale

The National Trust is launching a £1.2m appeal to help secure the future of one of the most famous and beloved landscapes in the UK, the white cliffs of Dover.

The Trust already manages almost five miles of the cliffs in Kent but has been offered the chance to buy a one-mile long "missing link" overlooking the port.

Owning the land would create a wonderful walk between the trust's visitor centre and the South Foreland lighthouse. But it would also make it easier for the trust to do more to preserve and improve the rare chalk grassland, an important habitat for rare flora and fauna.

Fiona Reynolds, the director general of the National Trust, said the appeal was the trust's biggest ever for a coastal site.

She said the cliffs were one of the great symbols of the nation, adding: "If we don't raise the money then the future of the white cliffs is uncertain and this stretch of coastline might one day be disrupted by inappropriate management or development."

As well as being a hugely important historical and cultural site, the cliffs are home to a rich array of wildlife, including the adonis blue butterfly, rare coastal plants such as oxtongue broomrape and sea carrot, and birds like the skylark, kittiwake and peregrine falcon.

Nic Durston, the trust's assistant director of operations in London and the south-east said the section at the centre of the appeal was the most visible. "It's there in all its glory as you leave and enter the port of Dover. When people think of the white cliffs, this is the section most envisage."

The historian and television presenter Dan Snow, who is supporting the appeal, described the cliffs as "am amazing part of our national story".

"When I was a kid they were the last thing I'd see when we were leaving for our camping holidays in France; they were the first thing we'd see coming home.

"They are what the Grand Canyon is to the USA or the Niagara Falls is to Canada. The landscape runs like a thread through British literature, art, film-making. They are entwined with our national story politically, a symbol of defiance against tyranny, against European dictators like Napoleon and Hitler."

Snow has often walked the cliffs. "It's joyful to be by the sea and look out at France, to see how close we are to our European neighbours, to watch those ships pouring through the busiest shipping lane in the world. It's a wonderful place."

Across England, Wales and Northern Ireland, the National Trust looks after more than 720 miles of coastline. The trust acquired its first stretch of the cliffs in 1968. The funds for the missing section, which is being sold by a private landowner, need to be raised by the end of the year.