One of world’s best-known painting, Diego Velazquez’s Venus at her mirror (1644-48), hangs at the National Gallery in London, UK. In 2009 several of the National Gallery’s treasures were displayed in the streets of York. Not all of them produced the effect similar to the Spaniard’s painting. For instance, the Feast of Baltazar by Rembrandt, or paintings by Leonardo or Henri Rousseau were much more classical and didn’t hang in the place where a crowd of people were not expecting to stumble into them.
A similar project is currently going on in Moscow, for which I do not have all the details yet.