The National Trust has launched a £3m fundraising appeal to buy a stretch of Gwynedd coastline.
The money raised will fund the purchase of a 16 acre (6.47 ha) slice of natural beauty on the Llyn Peninsula between Henfaes and Porth Simdde as well as the cost of building a new visitor centre.
The trust said owning the land would protect it from "unsightly and inappropriate" tourist development.
It has set an appeal deadline of 30 September 2010.
Visit Wales, the tourist board, has already committed to providing 45% of the funds.
The appeal site pledges the move will ensure the protection of endangered wildlife, flora and fauna and the local way of life.
It claims the livelihoods of local farmers and fishermen could be at risk.
If the appeal target is reached, the trust also plans to use some of the cash to create a new link path to the Llyn Peninsula coastal path and create a new visitor centre which would provide seven new jobs.
A trust spokesman said: "A beautiful coastline and a way of life are under threat.
"If we can't acquire this coastline, it could fall into the hands of property developers seeking to exploit the area.
"This isn't a place for modern holiday apartments or tourist attractions. It's a place to enjoy unspoilt seaside vistas, quaint cottages and farms, and a traditional coastal way of life."
Llyn is home to a range of endangered species - 5% of the UK's population of the chough, a small crow with a curved red bill, is found there, while one spot is the only place on mainland Britain where the spotted rock rose survives, and there are also important colonies of eelgrass, a flowering marine plant.
Visit Wales said: "This is a very important stretch of coastline on the Llyn Peninsula.
"By matching the funding raised by the Neptune Coastline Campaign we hope to secure this area for local people and visitors to enjoy for many years to come."
Among the locals whose way of life is dependent on the coast and tourism is Colin Evans.
Mr Evans organises tourist trips to Bardsey Island and runs the supply boat to a lighthouse.
He said: "If a lot of land was in the hands of private developers you would see more caravan parks and things would develop overmuch.
"It would be good to have the National Trust as landlords and to have them so supportive of our traditional way of life."