Cullinan diamond mine is located in the Gauteng Province of South Africa. The site is situated about 40km east of Pretoria city in Cullinan. The diamond mine is also known as Premier mine.
The Cullinan Diamond is the largest gem-quality rough diamond ever found, weighing 3,106.75 carats (621.35 g), discovered at the Premier No. 2 mine in Cullinan, South Africa, on 26 January 1905. It was named after Thomas Cullinan, the mine's chairman. source