Hi Alex, that definitely sounds like Holocaust Education Trust. They select two from each school, and run trips in batches by Region (DD2 had to write a speal as to why she should be chosen). and they are fantastic trips. There are pre trip and post trip seminars with talks from survivors and MPs but if DD is standing in she will have missed those but it won't matter at all. They are accompanied by religious leaders and survivors and it was incredibly well run and organised. If they want to they can follow up with a project at school and take their involvement further but DD had so much on she just went on the trip and left it at that - but it was one of the best things she has done and was instrumental in her uni degree choice - as well as being good for PS and interview discussion topic.. And we paid something like £60 for the whole thing I think. Only down side was we had to get her to the airport at something like 5am and pick up at midnight !!
You can google the organisation if it is them - DD loved it as everyone on the trip was as interested as she was whereas sometimes on school trips half of the group just want to get to macdonalds !! It was exhausting too - so wear comfortable shoes - DD2 went at 5am the morning after doing gold Dof E which wasn't the best plan.
Of course it may be something else entirely.