The largest habitat restoration ever undertaken by the Nottinghamshire Wildlife Trust has begun.
Three years in the planning, work on Besthorpe Nature Reserve, an old gravel quarry, will cost about £350,000.
It will see the creation of almost eight hectares of reed bed and three hectares of wet grassland, plus new ponds and ditches.
The six-month project, which will close the reserve for three months, is aiming to attract rare birds and otters.
Funded by a major appeal, the project has also been backed national and local businesses.
Trust communications manager Erin McDaid said: "We have received tremendous support for this work and we hope to keep the disruption to a minimum but we will need to close the reserve to the public over the next three months to ensure public safety.
"However, we look forward to welcoming visitors back to the reserve over the spring and summer."
