Scott Weaver's Rolling through the Bay is cool! It is made completely with toothpicks.
You've probably made model houses out of popsicle sticks with your children. This man made a model of the entire city of San Francisco. And he decided to use toothpicks. He used more than 100,000 toothpicks and it took 35 years to build. Not only is it huge, you can take tours using little plastic balls. Prepare to be amazed.
I have had many hobbies over the years, but I cannot image having the patience to build one thing for 35 years.
Here's the website: https://www.rollingthroughthebay.com/
Here's the vimeo version.