Discovering the Berlin underground is definitely one of the coolest things you can do in the city. It is also a chance for you to learn about how life was during the war and how Berliners lived.
There are still rooms with beds, kitchen, old propaganda posters etc., and it makes you wonder how people lived in the past!
Tip: There are many tours available, but it is best to book in advance to be sure there is a spot left.
Example of an underground visit. There are numberous tours available, from going inside of a nuclear bunker to going under the Berlin wall.
Take a look into a bunker which forms part of a complex which would have sheltered thousands of Berliners during the Cold War.
Other exhibitions featured in Berlin Underground.