We are now standing on Mysia Street, in front of the free speech memorial. It's hard to imagine at first glance, but this unassuming location was once among the most feared and hated addresses in communist Poland. Mysia 5 was the headquarters of GUKPPiW and it stood for the Main Office for the Control of Press, Publications, and Public Performances,which was a very long way of saying the state Censorship Office. For decades, every book, newspaper, magazine, song lyric, even wedding announcement intended for print had to get past the pencils of Mysia. Picture rows of drab bureaucrats here whose sole job was to read, redact, and reject anything that didn't fit the Party line. Articles about shortages? Censored. Criticism of the Soviet Union or Poland's government? Definitely censored. Even innocuous things could get cut if deemed too religious or too Western. Editors back in the day knew that when they submitted a newspaper proof to Mysia, it would often come back with whole paragraphs blacked out. Sometimes they'd intentionally leave blank spaces to clue readers in to the meddling. The original building where this office was housed was demolished. At that time it was effectively the Ministry of Truth in Warsaw's Orwellian reality. But the Poles operated a massive clandestine publishing network. It is said that hundreds of independent publications circulated secretly from political essays to poetry. Those risking it knew if they were caught, Mysia’s enforcers would seize and destroy their work, and worse. Free speech was one of the key demands of the solidarity movement which originated here in Poland, though in a different city and that movement began the unraveling of the entire Eastern Bloc. When the communist regime fell, one of the first laws was the abolition of censorship. Poland's press and artists were finally free to speak their minds. Today, Mysia Street has transformed into something of a symbol of victory over censorship.The Free Speech Memorial itself is subtle: a black stripe of pavement crossing diagonally and then rising upward like a broken barrier. This monument, unveiled about a decade ago by Poland's president, represents a censor's line being shattered – a pen stroke that can no longer contain the truth. It marks roughly where the old censorship office stood and commemorates Poland's hard-won freedom of expression. It’s also notable that Mysia means “mouse” in Polish. And indeed, this was a little “mouse hole” from which big, bad censorship peeped out. Now that mouse is gone for good. Onwards to the finale of our tour and the most unmissable monument in Warsaw, the Palace of Culture and Science.