The mini-series is kicked off by the issue in honor of the Royal Greenhouses of Laeken.The nineteenth century was characterised by industrial revolution, inventions of new building techniques with new materials such as steel and glass. This development resulted in a new type of building: the conservatory. In total, the Royal Greenhouses consist of 36 pavilions made of glass and green-painted iron, covering a total area of 2.5 hectares. All in harmony with the old orangery and the classical style of the castle buildings.