Beavers will be released at two sites in the south of England next spring, the National Trust has announced.
The reintroduction will be the first made by the conservation charity, with the aim of helping with flood management and improving biodiversity.
Two pairs of the rodents will be released - one near Exmoor in Somerset, and the other near the South Downs.
Beavers became extinct in the UK in the 16th Century when they were hunted for their fur, meat and scent glands.
The plans, approved by Natural England, will see Eurasian beavers released into fenced areas of woodland at Holnicote in Somerset, and at Valewood on the Black Down Estate, on the edge of the South Downs.
"Our aim is the beavers become an important part of the ecology, developing natural processes and contributing to the health and richness of wildlife in the area," Ben Eardley, project manager for the National Trust at Holnicote said.
"Their presence in our river catchments is a sustainable way to help make our landscape more resilient to climate change.
"The dams the beavers create will hold water in dry periods and help to lessen flash-flooding and reduce erosion."
David Elliott, lead ranger for Valewood, described beavers as "nature's engineers" and said they could "benefit a host of species".
Both projects will be monitored, in terms of ecological and hydrological changes to habitat, with help from Exeter University
The releases are part of the National Trust's wider plan to restore 25,000 hectares (62,000 acres) of "wildlife-rich" habitats by 2025.
Small populations of beavers have been re-established by UK conservationists in recent years, including on the River Otter in Devon.