The site of the grave was hidden beneath rubbish at the cemetery
A grave containing 200 people who donated their bodies to medical science in the 1970s is to be dedicated.
The discovery of the large unmarked grave at Arnos Vale Cemetery in Bristol was only made in the past two years.
The previously hidden grave had been neglected and had been used as a rubbish dump for "many years".
But volunteers from the Arnos Vale Cemetery Trust worked to clear the area and a new plaque will be unveiled later in June.
The grave was one of many areas of Arnos Vale which fell into a state of neglect before the cemetery was bought by Bristol City Council in 2002.
Arnos Vale has recently been the focus of a £5m project to restore the 171-year-old cemetery.
It is regarded by many as one of Britain's finest Victorian garden cemeteries.
The grave where the medical science bodies are buried was discovered following an enquiry by a man who was trying to locate his father's grave.
Arnos Vale Cemetery opened in 1839
More than 300,000 people are thought to be buried there
First person buried there is Mary Breillat, the wife of the man who brought gas street-lighting to Bristol
In 1987, private owners wanted clear a large section of the cemetery for a commercial development
The site was bought by Bristol City Council in 2002
It is now under the care of Arnos Vale Cemetery Trust
Following a £5m restoration, it reopened in 2010
The call sparked a hunt which was carried out by the cemetery services officer Sue Mackenzie who pinned the location down to plot C905 which was not marked on any maps.
Her search led to a stone mason who had dug the original grave who then led her to the spot.
Cemetery spokeswoman Sarah Cox said: "It was purely by chance that it was discovered as the plot wasn't anywhere to be found.
"There are no markers despite more than 200 people being buried there."
Work to clear the grave had taken 18 months to complete and the dedication ceremony will be conducted by an interfaith minister.
Members of the families of those buried in the grave attend the service as well as the volunteers who help to clear it.
The cemetery says the dedication is invitation only but anyone who believes a family member might be buried there is being urged to get in touch.