The wall was a physical marker of the ideological divide between the repressive communist regimes in the East and the democratic capitalist West.
Built in 1961 to stop East Germans fleeing to the West it fell on November 9, 1989. Its fall was a historic moment that symbolised the crumbling of communism in Europe.
"The fall of the Berlin Wall is a well-known fact everywhere, but not that many people realise that there would be no fall of the Berlin Wall without what happened in Poland before," former Polish defence minister Janusz Onyszkiewicz, an international affairs expert, told Radio Poland.
Five months before the wall collapsed, Poland had already held its first partially-free elections after World War II.
The vote precipitated a domino effect across the region, culminating in the fall of the Berlin Wall in November that year.
See this story for more details.