The Library can be approached without any problem during the event that will take place in Buda Castle from Thursday to Sunday. NSZL will wait for you with its services and exhibitions.
[1]The Beer Festival will take place in the territory of Buda Castle from Thursday June 2 to Sunday June 5, between 10 a.m. and 8 p.m. During the Festival you can approach National Széchényi Library without any problem, by simply presenting your Reader Pass. If you wish to visit our exhibitions [2] or listen to the concert of the Library Choir [3], we kindly ask you to tell about it at the entrance of the Festival, and then you will be free to walk through to the building of National Széchényi Library.
Links:
[1] https://oszk.hu/sites/default/files/bak-sor.png
[2] http://www.oszk.hu/en/temporary_exhibitions
[3] http://www.oszk.hu/en/news/concert-library
[4] https://oszk.hu/en/category/foszotar-es-pozicionalo/hirek