A new 'super nature reserve' is being created across 15,000 acres of Somerset to protect saltmarsh, heath and wetland habitats.
The area in the Somerset Levels, Moors and coast is home to rare and threatened species including skylark, bittern and avocet.
And it is also the second largest area of lowland peat in the UK, providing a significant carbon store, according to Natural England.
The move extends the existing National Nature Reserve by 56% to 6,140 hectares and brings together six reserves including Bridgwater Bay, the Huntspill River and parts of the Levels.
The new Somerset Wetlands reserve is only the second 'super' National Nature Reserve to be designated in England, following the creation of Purbeck Heaths, Dorset, in 2020.
It comes on the 70th anniversary of the creation of England’s first nature reserve and is part of efforts to create a 'nature recovery network' across the country, to create larger and more joined-up areas for wildlife.
Tony Juniper, chairman of Natural England, said: “The creation of this very large National Nature Reserve is an important moment for nature recovery in England.
This is not least because it presents a practical demonstration of what can be done by working in partnership across the landscape at scale to reverse nature’s decline.
“70 years from the creation of our first National Nature Reserves in England, these wonderful places are needed now more than ever, as we face into the challenges of global warming, wildlife decline and reconnecting people with the natural world.”
Craig Bennett, chief executive of The Wildlife Trusts, said: “Super National Nature Reserves provide a great opportunity to engage a wide range of people, including private landowners, to tackle some of the issues affecting our nature reserves that need action to be taken at a landscape scale.
“If we are to achieve nature’s recovery, we need to create and restore wild places across the countryside, giving wildlife the chance it so desperately needs to spread and thrive."