Spomenik #1 (Podgaric, Croatia), 2006. Photograph: Jan Kempenaers Commissioned by Tito to commemorate this World War II battle site and designed by Croatian sculptor Dušan Džamonja in 1967. This superstructure is seen by just handfuls of people, brave enough to explore the nether regions of the Balkans.
One Way Colour Tunnel by Olafur Eliasson. This is a tunnel made up of light-shattering translucent and reflective triangular panels of coated acrylic, resembling a walkway of stained glass. It can appear monochromatic from one angle or multi-colored from another angle. This is at the San Francisco Museum of Modern Art.