FEZ Berlin is a huge family and youth centre in Volkspark Wuhlheide, built in the late 1970s as the GDR's Pionierpalast Ernst Thalmann. The complex still has a strong East German period feel, with theatres, workshops, a swimming pool, and space-themed activities spread across a large modernist campus.
It is most useful for families, but anyone interested in everyday GDR architecture will find it an unusual stop away from central Berlin.