Why was the Berlin Wall erected in Berlin?

Question

I understand the divide between East and West, but why was the Wall erected specifically in Berlin?

In: Other

Answer 1

It was to stop a brain drain. A big problem for the DDR (East Germany) was that a lot of their highly educated citizens could defect very easily by pretty much walking into West Berlin and applying for FDR (West German) citizenship.

So, the decision was made to build the wall around the western part of Berlin in order to prevent this from happening