The National Trust trust fears access to Bantham beach and the Avon estuary could be reduced and the coastline could be at risk of inappropriate development if another buyer snaps up the estate, which is on the open market.
The Trust has already been able to commit £4.6 million from its Neptune campaign to protect coastal areas, but urgently needs to raise another £2.6 million to buy the beach and estuary and pay initial management and conservation costs.
This is a magical place, a true jewel on the South West coast.We now have a once in a lifetime opportunity to permanently secure and protect the landscape of one of the least spoilt coastal sites and secure its future for everyone to enjoy.
If we don't raise the money then the future of Bantham beach and the Avon estuary is uncertain and this stretch of coastline might one day be disrupted by inappropriate management or development.
If it buys the land, it plans to maintain access for visitors and conserve the landscape of the flooded river valley, enhancing the oak woodlands that sweep down to the estuary and sowing wildflower rich meadows.
More top news
Britain's Heather Watson could face the game of her life after her second round Wimbledon win set up a possible match with Serena Williams.
Police have offered legal advice to anyone who spots a dog trapped in a hot car - including on whether they can smash the windows or not.
Sir Nicholas Winton, who rescued 669 children from the Nazis, didn't tell anyone about his exploits for 50 years - not even his wife.