Here is some wonderful home-movie footage, shot by a camper at Butlins Clacton in 1970, and kindly posted by "Cinebolex" on YouTube.
The first 3
mainly concentrating on
the activities of the little boy from the family who took the footage;
then, for the last 54 seconds, we get to see more of the general
on the Entertainment Programme, such as the Swimming Gala in the
L-shaped pool, and the Children's Sports Day.
[The quality is good enough to switch to "full screen" when viewing.]