There are some universities that offer opportunities for adult education. Istanbul Technical University for example offers courses for adult education in various fields- from music to computer education. Many of the courses may however be in Turkish. For more detailed information, check the official website: http://www.itu.edu.tr/en/home.
For a listing of universities in Istanbul, click here: http://en.wikipedia.org/wiki/List_of_universities_in_Istanbul
Update 12/06/2014
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