The memorial to the victims of the March 11, 2004 attacks sits right inside Atocha station. Above ground is an 11-metre glass cupola, below it a room you enter from the main lobby. From inside you can see messages printed on the glass, the same ones people wrote in the days after the bombing.
The cupola is built from clear glass blocks glued with an acrylic adhesive that cures under ultraviolet light and stays transparent. An ETFE membrane on top lets through 97% of light. By day the messages read through the glass skin, at night they look different. The room inside is blue.
