Rickmansworth School's new pool is open to under 19s and over 60s for free this summer.
Three Rivers District Council is offering residents free swimming sessions at the new Scots Hill facility.
Under 19s can use the pool on Wednesdays and Fridays from 10.30am to 11.30am and over 60s can use it on Tuesdays and Thursdays from 1.30pm to 2.30pm until Friday, August 29 for free.
The district’s free swimming initiative is also in place at Sir James Altham Pool, in South Oxhey, Watford Leisure Centre and William Penn Leisure Centre. For more information contact the centres directly.
Chris Lloyd, chairman of the council, said: "The new school leisure facility looks fantastic. I would like to encourage us all to do more sport whether we are young or old."
Hertsmere Leisure will be managing the public sessions, which will run until Friday, August 29 between 10.30am and 2.30pm week days only.
During these times the pool is open for all casual swimmers.
The cost for swimming during these times for adults is £3.60, whilst juniors and senior citizens pay £2.10. Children under three years old can use the facilities for free.