A large chunk of countryside above the White Cliffs of Dover is at risk - if the National Trust cannot raise £1 million in three weeks.
The Trust manages the five miles of the cliffs and bought a mile section in 2012 to protect the area.
However, according to the Telegraph, the Trust recently learned that the landowner is planning to sell the managed area, sparking fears that the huge piece of land above the cliffs will be changed forever by developers.
The National Trust has launched an appeal in a bid to raise the money to buy the land from the owner. General manager of the white cliffs, Virginia Portman, said she would be "devastated to lose this opportunity".
The White Cliffs of Dover is an iconic UK landmark, playing an essential part in our military history.
Dame Vera Lynn, 100, who famously sang about the landmark during World War Two, is backing the National Trust's campaign.
She became known as the Forces' Sweetheart with her performances of the 1942 hit The White Cliffs of Dover.
According to the BBC, she said: "They were often the first sight of home for our brave boys.
"They continue to represent important British ideals such as hope and resilience even in the most difficult of times.
"It is vital that we do all that we can to preserve this important historical site."
The 700,000 square metres of land are an important habitat for butterflies as well as the peregrine falcon and the skylark.
The site is also home to several structures from World War Two, including two gun emplacements. The National Trust wants to make sure the area is something the whole nation can enjoy, creating access routes for visitors, making the structures watertight, and restoring the chalk grasslands.
It's believed the land, adjacent to Wanstone Battery, costs around £2.5 million and The Trust is using money from its Neptune coastal fund towards the cost of purchase, reports the Telegraph. But the fund needs to be boosted with a further £1 million by September 22 to secure the land, owned by a local farmer.
Ms Portman added: "This unique coastal habitat should be open for the whole nation to enjoy.
"I'd be devastated to lose this opportunity to protect it forever."