Stubbington
I am not sure what to call this, other than a school trip.
That will immediately give the wrong impression though. Today school trips can be skiing in Utah or some other far away place. Even a short cruise, although to be fair, there were some educational cruise ships around when I was at school. Somewhat different to the cruises today.
Stubbington, in Hampshire was only a tad under 18 miles from school. A week away from home in some wooden huts. At least the beach was not far away. Lee-on-the-Solent was a little further than the beach but was still walkable.
Amazingly, there is still something left of the site. It is called Stubbington Study Centre, and is still run by Hampshire County Council. The video below shows some of the 80 years history.
Looking at the video brings back some memories. I could even be in some of the still photos.