A pair of Eurasian beavers have been released on Exmoor in a National Trust effort to curb flooding and improve biodiversity.
The male and female were released in a fenced woodland on Holnicote Estate.
Project manager Ben Eardley said: "As ecosystem engineers the beavers will develop wetland habitat, increasing the variety and richness of wildlife."
In recent years, beavers have been released in handful of sites across the UK by conservation groups.
The beaver release is the first of its kind by the National Trust, which is also planning another release in the South Downs.
Mr Eardley added: "Their presence in our river catchments is a sustainable way to help make our landscape more resilient to climate change and the extremes of weather it will bring.
"The dams the beavers create will slow the flow, holding water in dry periods which will reduce the impact of drought.
"They will help to lessen flash-flooding downstream."
Mark Harold, director of land and nature at the conservation charity said: "We need to work with natural processes in the right places.
"This is a different way of managing sites for wildlife - a new approach, using a native animal as a tool."
Once settled, the beavers will build a lodge or burrow and then begin to modify the enclosure to suit their needs, allowing them to move around freely through the water and access food.
They have been examined by wildlife vets and specialists and met all screening requirements.
The National Trust will work with Exeter University to monitor the rodents and document how the habitat changes.