If you do not want to go abroad for a longer period of time, you can opt for a summer school or an international course. These courses are often organised internationally or in collaboration with the university, and can fit in the framework of the Erasmus programme.
Some faculties offer credits for the successful completion of such a course. Please consult the regulations of the faculty / department for more info. The Faculty of Business and Economics publishes a brochure with a list of summer courses that might be eligible for credits. More information is also available on Blackboard under 'my organisations' - 'internationaal studeren FTEW'. The Faculty of Social Sciences also encourages these individual learning paths.
You can contact the International Relations Office for more information. See below for an overview of summer schools and other courses on offer.