A "no-protest zone” is a certain area around the offices of constitutional bodies in which political demonstrations and other public gatherings are fundamentally forbidden. In Germany, there are no-protest zones around the Bundestag (lower house of parliament), the Bundesrat (upper house of parliament), the Federal Constitutional Court and the state (Länder) parliaments. Exceptions to the no-protest regulation can be made for public festivals or religious celebrations by agreement with the head of the constitutional body in question.
Why do these zones exist? They are there to protect the constitutional bodies and to allow them to work without any direct pressure from the populace, such as that exerted by a demonstration, for example. At elections, there is also a zone around polling stations in which parties are not allowed to carry out any campaigning activities. As a rule, such zones have a radius of between 10 and 50 metres.
During the Middle Ages and later, German cities also set aside a certain area around a city (a "Bannmeile”) in which traders from other places were not allowed to offer their wares for sale. But this "Bannmeile” was removed on big market days.