Round-the-clock swimming takes place at Hathersage Pool to mark the summer solstice.
The pool will be open from 3.30am on Friday, June 21, to 3.30am on Saturday, June 22.
Jo Wiman, of Hathersage Parish Council, said: “The exciting event is being held for the first time and will give swimmers or spectators the opportunity to swim or watch as the sun rises and sets.
“What could be more spectacular than swimming in beautiful surroundings through the night and as the sun rises over the rocks of Stanage Edge and bathes the pool in light?”
Ms Wiman said the pool is seeking swimmers interested in taking part in a sponsored swim during the solstice session, to help good causes.
She said: “Could readers of The Star swim a mile at midnight or take part in the gruelling challenge to swim 1 mile every hour for 24 hours?”
The pool is also open to general swimmers, too.
Normal ticket prices and season passes apply and further details are available by emailing email@example.com or calling the pool office on 01433 650 843.
■ The South Yorkshire Branch of the Royal Life Saving Society is holding free life-saving safety sessions on Saturday, June 22.
The event takes place in the pool at Dearne Valley Leisure Centre, Doncaster Road, Denaby Main, Mexborough.
A spokeswoman said: “We are holding various sessions on the day which teach children personal survival, rescue and CPR skills.
“We are also holding Save A Baby’s Life sessions for adults which teach child and baby CPR skills. These sessions are suitable for anyone who looks after children.”
To book a place, emailRLSS.SYbranch@gmail.com or call Kim on 07930 574 855.