Scott Weaver’s Rolling through the Bay, an homage to the city of San Francisco, is made of over 100,000 toothpicks and Elmer’s glue, and was built over 35 years time. This structure was temporarily featured and filmed in The Tinkering Studio at the Exploratorium a few years ago. If you’re in or visiting San Francisco, put The Exploratorium at Pier 15 on your must-do list. It’s amazing.
You can see photos of Weaver’s structure at Where Cool Things Happen. And there are more cool structures in the archives, including K’nex Clockwork, some excellent wood marble machines, and DIY paper rollercoasters.