Berlin

Alexanderplatz - Originally a cattle market and military parade ground, it had been heavily bombed in World War 2 and later became part of East Berlin.
Altes Museum - It was built between 1825 and 1828. The museum houses items of antiquity, and a great collection at that.
Berlin Cathedral - It was built between 1895 and 1905 and is the largest Protestant church in Germany.

Cologne

Cologne Botanical Gardens - It is one of the best loved areas of greenery in the city.
Cologne Cathdedral - It is the second-tallest Gothic structure in the world.
Cologne City Museum - Its remit is to cover the history of Cologne, focusing on its most important aspects.
Cologne Zoo - It features over 7,000 animals of more than 700 species on more than 20 hectares.

Hamburg

Hamburg Town Hall - It is a beautiful neo-Renaissance building dominating the city centre with its ornate facade.
Hamburg Kunsthalle - It has a vast collection of paintings and sculptures which date from medieval times to the present.