There have been close calls in the past — two locals in 2001 struck what they think was a supporting tunnel wall while digging near a local railway for the secret shaft. (travelandleisure.com)
Prism material lets buildings subtly change colors and patterns on the spot, without having to rely the more traditional LCD displays that are found at the O'hare tunnel walls in Chicago. (goodereader.com)
It can be used to subtly change colors and patterns on the spot, without having to rely the more traditional LCD displays that are found at the O'hare tunnel walls in Chicago. (goodereader.com)