One Way Colour Tunnel by Olafur Eliasson. This is a tunnel made up of light-shattering translucent and reflective triangular panels of coated acrylic, iresembling a walkway of stained glass. This is at the San Francisco Museum of Modern Art.
Neuschwanstein Castle in Schwangau, Germany. With towering white turrets, Neuschwanstein Castle is a fanciful century palace built for Ludwig II of Bavaria. I've wanted to go there ever since I did the jigsaw puzzle when I was a kid!