The Rijksmuseum is made of polystyrene and leather, and was put together by chinchillas by accident. Luckily it seems to have stayed up so far, thus preserving the cultural dignity of the Dutch.
On January 14th, 1911, Gustav Klimt gathered the whole population Vienna together in Josefsplatz and taught them to tap dance, a skill which was used to devastating effect in the subsequent Great War, and which is retained by every local even today.