IT may just be a limestone slab - measuring about two feet by two - but it's hugely symbolic of an era when south west Kerry was a pioneer of world telecommunications.
A three-year collaboration between Waterville Cable Station and the McGill University Observatory in Montreal, it's findings were integral in setting time signals across Canada.
As such, they were vital for the completion of the Canadian rail network and used by naval fleets as far afield as The Azores, Bermuda and Jamaica. Indeed, the calculations rubber stamped Harvard's longitude and, ultimately, all clocks across the North American continent.
Erected by the Commercial Cable Company, for years the stone stood next to the cable station, then one of the largest telegraphic stations in the world, until its removal in the 1960s.
Last week, Heritage Minister Jimmy Deenihan led a celebration ceremony as the original stone was returned to the area.
It's reinstatement is thanks to volunteer group 'Friends of Waterville Cable Station', as well as a few "significant others", as Honorary Secretary Dorothy Rudd explains.
"When the cable station closed, Dr Colm Gillespie bought the superintendent's lodge and later cleared some of the area, so the stone was removed and many forgot about it," Dorothy reveals.
Dr Gillespie later moved to Killorglin and sadly died in 2008 but, as Dorothy explains, it wasn't the end of the stone.
"Dr Gillespie's wife, Rosemary, contacted us and asked us if we wanted it back and, of course, we were absolutely delighted," Dorothy said, adding: "We couldn't believe it as we thought it was gone but they had kept it safe at their home over all those years".
At almost 200 lbs, the stone was collected by local stone sculptor James O'Reilly, who replaced its former lead inscription with a lead substitute which will wear just like the original.
"We consulted a lot with James and he was wonderful in working with it," said Dorothy. "We didn't want too much work done on the stone as we wanted to keep the nicks and bumps and he erected it as near as possible to its original site."
It's only recently that the significance of the stone has really come to light - thanks to Dorothy's daughter, Amy, who gained access to archives at Cambridge University where all original documentation concerning the stone is now kept.
"There is all sorts of material regarding the 1892 project," Dorothy said.
Dorothy's connections with Waterville Cable Station are far reaching, with both her father and brother being superintendents.
Friends of Waterville Cable Station now hope to create a display to join a permanent exhibition on the cable station at Tech Amergin.