A 500-piece jigsaw puzzle, size 20"x16", to build the world's largest diameter tunnel, in Seattle, Washington, USA. Beautiful custom box includes: a study cotton drawstring bag, a true brass polished hanging pendant which tells the interesting story about the safety measures used by underground miners on a large magnitude project, a full-size laminated glossy poster which serves to help the maker in their puzzle creation. Additionally, two postcards tell this story and the history of the giant tunnel.