Since December 1924, Kimberley's tourism industry used this fact as its biggest selling point, and thousands of tourists have visited the Big Hole annually.
On Thursday evening, Steve Lunderstedt - well-known historian, author and tour guide in Kimberley - gave a talk on the subject at a meeting of the Historical Society of Kimberley and the Northern Cape.
Lunderstedt has done extensive research on the subject - and it appears the Big Hole has lost out on its claim to fame.
Reports of mining companies and mining inspectors have proved that the Jagersfontein hole holds the record for the biggest mining hole dug by hand in the world.
While journeying by train last year, he said he read in a magazine that the Jagersfontein hole held the record for the biggest mining hole dug by hand.
Has studied all Kimberley mines
That was when he decided to do research to confirm that Kimberley's Big Hole (officially known as the Kimberley Mine) was the biggest, but facts have proved otherwise.
Lunderstedt didn't limit his research to these two only, but also looked into all the mines in Kimberley, the Koffiefontein mine and several others.
The reports studied by Lunderstedt showed that in 1886, pickaxes and spades were used to dig down to a depth of 450 feet in the Big Hole.
Maps dating to 1890 and 1891 showed opencast work here had reached no deeper than 500 feet.
A depth of between 450 feet and less than 500 feet was reached, but not 500 feet.
In an 1889 report, a mining inspector confirmed that 510 feet (opencast, no shafts or tunnels) had been reached with pickaxes and spades in 1988 at the Du Toitspan mine in Kimberley.
As recorded by the mining inspector, the depth of the Bultfontein mine in Kimberley reached a record depth of 620 feet in 1888 with pickaxe and spade - deeper than the Big Hole and the Du Toitspan mine. It didn't get any deeper because a rockfall covered the opencast section in 1889.
Lunderstedt said he couldn't uncover a comparison between the mines in Kimberley anywhere in his research.
It seemed as if it was simply accepted that the Big Hole was the deepest.
The Jagersfontein mine (660 feet in 1911) is the only diamond mine ever laying claim to being a deeper hole, dug by hand, than Kimberley's Big Hole.
Information indicates that the final depth of the Big Hole (opencast) reached 720 feet.
Stemming from the information Lunderstedt has studied, the conclusion is that the biggest man-made mining hole is Jagersfontein mine, followed by Bultfontein.