The more times I go stroll around this place, the more I like it. It is "The Crystal Palace" in Madrid's biggest park: El Retiro. Once more, here I am giving some good name to my city (for free ;-)
Thank you so much for your comments! Unfortunatelly, the inside is empty and not open to the public much of the time. They open it when it hosts exhibits and such.
Have you any photos of the inside?