They are known as one of archaeology’s great enigmas – hollow 12-sided objects from the Roman era with no known purpose or use.
Only 33 of these mysterious dodecahedrons have ever been found in Britain and now one, unearthed during an amateur archaeology dig after 1,700 years underground, is going on public display in Lincoln as part of a history festival.
Found in Norton Disney, near Lincoln, in the summer of 2023, the artefact is one of the largest of its kind ever found, measuring 8cm tall and weighing 254g.
Its excavation was particularly important as it was found where it was placed 1,700 years ago, meaning the site could hold clues as to its purpose. Only three other examples of dodecahedra have been found on archaeological excavations.
Richard Parker, the secretary of the Norton Disney History and Archaeology Group, which found the item, said historians were no closer to finding out what these objects were despite extensive research.
“The imagination races when thinking about what the Romans may have used it for. Magic, rituals or religion – we perhaps may never know,” he told the BBC.
There are no known descriptions or drawings of dodecahedra in Roman literature, making their purpose unclear.
The Norton Disney group said the objects were not of a standard size so were not measuring devices, and they did not show signs of wear so they were not used as tools.
It added that “a huge amount of time, energy and skill was taken to create our dodecahedron, so it was not used for mundane purposes”.
The Norton Disney dodecahedron, made of a copper alloy, is the only example found in the Midlands. It is in excellent condition, with no damage, and finished to a high standard.
Parker said it was found on the top of a hill in a former large pit of some kind and seemed to be deliberately placed there.
The amateur archaeologists who uncovered the object plan to return to the site this summer to try to uncover more clues as to why it was there.
The group was able to only partly excavate the trench where it was found in 2023, along with some fourth-century Roman pottery, owing to time and financial constraints, with the dodecahedron found on the penultimate day of the dig.
They have secured permission to return in 2024 and resume excavation, relying entirely on donations to fund their work.
The Norton Disney dodecahedron has been on display in the National Civil War Centre at Newark Museum in Nottinghamshire, and from Saturday it will be at Lincoln Museum as part of the city’s Festival of History.