If you're thinking about studying English this summer, the information below might be helpful to you.
- British Council Accredited English Language Centres http://www.britishcouncil.org/education/accreditation/centres
- English UK Accredited English Language Centres https://www.englishuk.com/en/course-finder
NL: English in academic courses - Utrecht Summer School: http://www.utrechtsummerschool.nl/
And here you can find some feedback about a few schools from students who have gone abroad to study English recently: