Whether you went swimming, played five-a-side or spent a day there with your school, it was a huge attraction from the day it opened in 1972.
Join us as we look back to 10 photos from the Hartlepool Mail archives and tell us if they bring back memories for you.
1. Agile in 2005
These youngsters were taking part in an agility session 18 years ago. Photo: LH
2. Skipping back to 2017
The Hartlepool Skipping School finals at Mill House Leisure Centre 6 years ago. Did you take part? Photo: Stu Norton
3. Teeing off in 1991
Castle Eden golf professional Tim Jenkins, instructing young champions (left to right) Simon Richmond, Matthew Emmerson and Gareth Rayner at Mill House Leisure Centre 32 years ago. Photo: Hartlepool Mail
4. In the swim in 2004
It was 19 years ago when British swimmer Chris Alderton passed on his knowledge to these youngsters at a Mill House session. Photo: SH