That's hard to measure. Events such as the construction of the wall, the shooting of Peter Fichte (shot in the death strip, left to die was all filmed), the tank stand off at check point charlie in October of 1961, JFK's visit, Reagans visit. Stories of escape attempts such the famous image of Conrad Schuman a solider jumping the barbed war.

All these events brought international attention. Berlin today is still synonymous with the wall.

How well the world knew, well it was no secret and the Berlin wall was the most obvious incarnation of the divide created by the Cold War. But we're still talking about a period from 1961 until 1989, so obviously interest and knowledge would vary depending on events and regions. It would be big news in western Europe and North America but how much the rest of the world knew or cared, I can't say.