Please see the link below for the (relatively new) CERN summer residential programme for school pupils. To be eligible, they have to be 16 or over on 24th July 2018, and can either have another year of school ahead, or have just finished school. There are 30 places, it’s open to the whole world, and all costs are covered so I suspect it will be rather competitive(!) but perhaps worth a shot? Application deadline is 5th February:
https://scool.web.cern.ch/content/about-programme
Of course there are also teacher programmes! :