In the winter of 1511, Brussels was buried in snow. Its residents responded by building snowmen. About 110 of them.

Except these were not really snowmen.

For several extraordinary weeks, the city filled with elaborate sculptures of knights, mermaids, unicorns, biblical figures, monsters and animals. There were also drunken figures, sexual scenes and some decidedly irreverent depictions of clergy and other authority figures.

Snow, it turned out, was an excellent medium for saying what you thought.

One sculpture appeared prominently near the Coudenberg Palace, home of the future Holy Roman Emperor Charles V. It depicted a maiden with a unicorn and has been interpreted by historians as a pointed reference to the young ruler, who spent much of his time away from Brussels.

Other sculptures poked fun at social conventions, religion, sex and everyday life. The result was part festival, part public art exhibition and part giant three-dimensional editorial page.

We know about this strange winter because Brussels city poet Jan Smeken documented it in a work now commonly translated as The Miracle of Pure Ice and Snow. His descriptions suggest that people traveled around the city specifically to see the creations.

And then nature closed the exhibition.

The temperature rose. More than 100 sculptures began melting at once, and the streets filled with water.

For a few remarkable weeks, however, the people of Brussels had turned their frozen city into a place where almost anything could be sculpted, mocked or celebrated. And unlike most political commentary, theirs conveniently disappeared when the weather warmed.