Seven automatic doors, each mirrored on both sides, are installed at equal distances down a mirrored corridor, one after the next and parallel to one another. The mirrors alter the perception of the space, and produce an endless reflection of the visitor, as she or he proceeds down the corridor, triggering the opening and closing of the doors. The sides of this third version—the first was installed in London at Tate Modern in 2003, and the second in 2006 at the Kanazawa Museum of 21st Century Art in Japan—are made of one-way mirrors, so as to enable the visitor to see outside the corridor while other visitors only see a reflection of themselves when they are outside the structure.