A wildlife haven is to be created near Stonehenge to help reverse the decline of England's chalk grassland.
The project should benefit rare birds like the secretive stone curlew
The Royal Society for the Protection of Birds (RSPB) plans to buy Manor Farm, a 731-acre site near the ancient stones, to coax back rare birds and insects.
The aim is to narrow the gap between Salisbury Plain and Porton Down, to create the largest network of chalk grassland sites in north west Europe.
The charity is launching a £2.3m appeal to raise money for the site.
The RSPB says about 80% of the country's wildlife-rich chalk grassland has disappeared.
The Manor Farm project will increase nesting opportunities for rare birds and benefit scarce butterflies and other insects found only on these sites.
The charity's conservation director Dr Mark Avery said: "This is the missing piece of the jigsaw for us and will be the RSPB's first major chalk grassland nature reserve.
"We all marvel at Stonehenge but forget the wonderful countryside around it. If our appeal is successful we will restore the area to its former glory and show other landowners its potential."
The appeal has been kicked off with £933,000 grant from the Heritage Lottery Fund.
The RSPB said rare birds including skylark, lapwing and the secretive stone-curlew should benefit from the purchase.
Stone curlew numbers plummeted after World War II because of modern farming methods, but this year the species reached a national recovery target five years early.
Butterflies likely to thrive include the Adonis Blue and Duke of Burgundy, which depend on plants such as horseshoe vetch and sheep's fescue, found only on chalk downland.