Number 6
It was built by the architect Léon Delune in 1904. He left his 'signature' on the house in a very unique way - his last name means 'of the moon,' in French, and he worked images of the different phases of the moon into the design. The big window at the top was originally designed so that there would be enough natural light for a painter's studio at the top of the building. It's located in Brussels, 6 Rue du Lac.