The world's largest spool of thread is located in Hamilton, Missouri. According to Atlas Obscura, it was unveiled in 2018 and stands 22 feet high and has an 8 meter diameter.
This mega spool can be visited at the Missouri Quilt Museum. The spool currently has over one million yards of thread on it!
What makes this giant object extra fun is that visitors can add their own thread to it. Feel free to bring your own thread if you visit, or you can buy some from the museum. I love that this is a collaborative project, and that it's ever growing! I wonder what it'll look like in a decade from now.