Christian camps
I am now a confirmed athiest anti-theist, and wasn't really a christian when a kid either, but 2 of the best holidays I had were with a friend at organised 'christian week' camp things in england.
We had a full week of electronics (building a whole host of different things that we wanted to), and software coding,
This was back in 1984/85 so it was coding my spectrum and amstrad, and the electronics was things like building infrared sensors, and fm transmitters and working them out in vero-board, etc.
It was great fun. And to be fair to he happy clappers, all the singing and christian stuff was confined to the evenings and optional.
I don't know who arranged them at the time but it was some national organisation - they were excellently organised with great accomodation (in a private girls boarding school in the SE) and if still going I'd recommend it to any 12-16yo techie.
stu