Gold medal winner Charmian Welsh trained at Dawdon Pit Pond in water from the County Durham mine
This is how swimming pools used to be.
Dawdon Pit Pond, near Seaham Harbour, in County Durham, opened in the 1940s.
It was filled with the water used to cool Dawdon Colliery's air compressors. It was always warm and filled with black silt.
The diving boards were equipped to Olympic standard. There was a bandstand, sandpit, loudspeaker and terraces for spectators.
The amphitheatre hosted swim galas, diving competitions and the pool was where thousands learned how to swim.
Watch this newsreel from the 1940s:
Charmian Welsh is one of those who fondly remembers the pit pond.
A far cry from the modern training facilities athletes enjoy today, she honed her diving skills in the black, silty water before going on to compete at the Olympics and win double Commonwealth Gold.
Now 85, living in Peebles with her husband John Stuart, where most are unaware of her sporting pedigree, she's been talking to ITV about her memories:
Charmian was told she was 'geographically misplaced' by a London diving coach because in the North East there were diving boards but no experts to teach how to use them.
During training, her mother would stand at the side of the pool shouting 'open' at the moment she needed to open out her dive to enter the water.
Charmian would clear a patch in the black silt below the diving board to create a white mark to aim for as she dived in.
She was 15 when she competed in the 1952 Helsinki Olympic Games, coming fifth for Great Britain.
Charmian was invited to America to train ahead of the Melbourne Olympics but was told if she went to America, "America could keep her", so didn't go.
In 1958 she won double gold in the Empire and Commonwealth games in Cardiff.
In 2022 Charmian's story was included in a new history book, marking the achievements of Northern Women.
Charmian told ITV Tyne Tees: "It never ceases to amaze me how after 60 years I am still remembered."