File photo - The Royal Greenhouses of Laeken are opened for the public next friday, April 14. Around 100000 visitors from all the world should come to visit this building made of glass and metal. The Royal Greenhouses of Laeken are a dream of the Belgian king Leopold II executed in iron and glass by his architect Alphonse Balat. Built between 1875 and 1905 they are still the most astonishing construction in Belgium and an important influence for art nouveau and present day architects. This green houses are located in Brussels city, 15 minutes from the downtown in the royal parc of Laeken where the King Philippe and the queen Mathilde are living. The area of the green houses covers 1,5 hectares. Photo by Olivier Polet/ABACAPRESS.COM