A colony of one of England's rarest beetles has been found hiding out in Sherwood Forest, Government conservation agency Natural England said.
The hazel pot beetle has been in decline across most of England since the 1960s and is all but extinct across the country.
The beetle, which is hard to spot as it hides out in the leaf litter in a self-made "pot" constructed out of its own dung, was absent from Sherwood Forest for 70 years until a chance sighting was made in 2008 by members of the public Trevor and Dilys Pendleton.
The sighting raised hopes the forest was offering a refuge for the beetle, which is one of England's largest and most endangered.
Following the discovery Natural England launched a three-year survey into the Sherwood Forest population, which was led by the Pendletons who are beetle enthusiasts, that found a population existed in good numbers and further populations could yet be discovered.
Dr Helen Phillips, chief executive for Natural England, said: "The hazel pot beetle has all but disappeared from most of England.
"The confirmation that a sizeable colony exists in Sherwood Forest is very encouraging news and we are working to develop more of the special habitat this beetle requires to help strengthen its numbers.
"We want to do all we can to ensure that this extraordinary creature can expand from its refuge in Sherwood Forest," she said.
The discovery is important because Sherwood Forest is the only site in the East Midlands, and possibly in the whole of Britain, that has current records of the rare and elusive beetle.