The Pez de Cristal ("Glass Fish"), the new Cercanías entry structure, is to be inaugurated on Saturday, 27 June 2009. It'll connect Atocha and Chamartin stations, creating the famed "Túnel de la risa".

ANOTHER UPDATE: The Inauguration WAS today at 11am, presided over by the President of the Comunidad de Madrid, Esperanza Guirre.

Apparently, the subsurface space is the largest man made cavern in the world, large enough to fit a 6-story building horizontally. The inauguration will end (????) nearly 5-years of construction and excavation in Madrid's Puerta del Sol.