Where in Germany did they fight World War 2?

Most German cities of any importance were bombed by British commonwealth and US air forces. Dresden was totally destroyed in one bombing to show their capacity, but most big cities were largely ruins at the end, especially in industrial areas.

In 1945 the eastern and western fronts had reached the German/Austrian soil, and were approaching Berlin from both sides, and troops entered from south, over the Italian border.

So the front line ran through almost all of Germany and even if some places escaped battle, they were occupied by allied forces very soon after the capitulation.

Notable locations of battle were at passages over Rhein (aka Rhine) and Berlin.