One of the most curious things about the home to Borussia Dortmund is located in the north end of the stadium, where less than 15 metres from the stand there is a small police station with two prison cells - one for the home fans (on the right) and one for the away fans (on the left).

"We made two in order to avoid any scuffles between the opposing fans" said a guide at the German stadium.

Each cell can hold up to 130 people.

They are soundproof to ensure the people they hold are truly being punished by not being able to hear what's going on with the day's match.