I concur with all the rave reviews but here’s an update: as of June 2020 the flag doesn’t work when you drop something in the mailbox within ... parallel, if you mail something from the mailbox atop/inside, it gets delivered with a stamp, “Sent from the World’s Largest Mailbox.” As such, buy or bring a postcard, sign it with year, and mail to yourself as a memento! My kids are so excited to get home and get their postcards with the stamp that says where they mailed it from as a keepsake for our fun road trip.
Definitely worth it to stop in Casey. It was a favorite for every member of our family. The Rocking Chair and Mailbox were the favorites - but there are MANY “World’s Largest” including pencil, wind chimes, golf tee, bird cage ... the little store across the street from the Mailbox has a map with the latest. You can also rent bikes there so you can ride between the attractions. We went right after they started opening post COVID so it was empty but driving from locale to locale would have otherwise taken time. I would allot a good chunk of time for cruising between and photos. There are also several places to eat which we are told are good but everything was closed when we were there so we didn’t get to eat as planned.
I share sentiments of other reviewers: not worth going out of the way for but if you have to stop, it’s a beautiful mural in a pleasant little town.