In the GDR the walls had ears, as is chillingly documented in this exhibit in the former Leipzig headquarters of the East German secret police (the Stasi), a building known as the Runde Ecke (Round Corner). English-language audioguides (€4) aid in understanding the all-German displays on propaganda, preposterous disguises, cunning surveillance devices, recruitment (even among children), scent storage and other chilling machinations.

　　All reveal the GDR’s all-out zeal when it came to controlling, manipulating and repressing its own people.