"To claim the title of World's Largest Mailbox, this structure had to be fully functional. As a working mailbox, guests have the opportunity to climb the stairs inside and send a letter of their own!

"There is also a fully functioning red flag that goes up when letters or postcards are mailed from the Mailbox. If you are looking for a great shot for your vacation album, then this is the place for you. Not only can your crew take a picture of you from down below, but you have a great view of Casey from up above.," the Big Things Small Town says.

"Bigger is not always better, but when you visit Casey, you might find yourself becoming enamored with many everyday items that are larger than life, including the world’s largest mailbox in Illinois. This little town has tons of “world’s biggest” things, and one of its most charming is the World’s Largest Mailbox," the Only In Your State says.

"One of the most charming projects was the World's Largest Mailbox, which was completed in 2015. The record-breaking mailbox measures 5,743.41 cubic feet, and it's designed to look exactly like a regulation, residential mailbox.

"Visitors can climb the stairs inside the hollow support post to stand inside the mailbox itself. The interior is plenty roomy, and you can even mail a letter while you're here! Tourists come from all over the world to climb up into the World's Largest Mailbox and wave at bystanders below."

"The mailbox and the downtown are only a couple of miles from the exit, which was very convenient. And it wasn’t hard to spot. The two-story white rural mailbox structure stood out with the blue sky behind it," the Linns Stamp News says.

"After climbing the steel grate stairs inside, you see a slot for dropping mail in. The mail falling in the slot triggers a set of pulleys that make the red flag go up. Pretty cool for those watching below.

"The added surprise came a couple of days later when I received the postcard I sent to myself, shown here. A handstamp indicating it was sent from the “World’s Largest Mailbox” was privately added before the card was turned over to the U.S. Postal Service."

"For a town of about 2,300 people, Casey has some big things to offer — literally! This small southern Illinois town is home to 12 Guinness World Record-holding attractions, plus a lot of other oversized things to see. Casey also has some truly unique eateries and the most beautiful city landscaping I’ve ever seen. The extra thought and care really added to the experience and shows how the entire town has embraced this larger-than-life gimmick," the Olio In Iowa says.

"An essential part of any visit to Casey is sending a postcard from the World’s Largest Mailbox. In order to qualify for the Guinness World Record title, the mailbox had to be fully functional, meaning it had to actually be a place where you could send mail.

"Visitors can climb up inside the mailbox for a view of downtown before dropping their letters in the mail slot. This big mailbox even has its own postage cancellation stamp and a giant red flag that raises when a letter is dropped in. Luckily for the local mail carrier, all of the mail posted here drops down into a locked compartment at ground level so they don’t have to constantly climb the stairs."

"One of the biggest of the big things in Casey is the world’s largest mailbox. Certified as the world’s largest by Guinness World Records on October 20, 2015, it measures 5,743.41 cubic feet and follows the design of a standard post mount mailbox to the letter," the Silly America says.

"The best part? This giant mailbox really is a mailbox! Hidden away in the post is a secret staircase that allows visitors to climb inside. Waiting at the top? A mail slot to drop your postcards to home. The big red flag on the side even raises up and down whenever anyone mails a letter.

"Like all the other giant attractions in Casey, the biggest mailbox in the world was created by Jim Bolin, who originally came up with the idea to create a giant wind chime to lure people off the highway and into Casey. His plan worked so well that one big thing turned into another. And another. And now, an entire town is filled with weird, wacky, and wonderful roadside attractions."

"The town of Casey, Illinois is no stranger to breaking world records—it's home to the largest chair in the U.S.—and the world's largest mailbox, which was created as part of businessman Jim Bolin's Big Things in a Small Town workshop," the newsbreak.com says.

"Measuring a whopping 5,743.41 cubic feet, the Casey mailbox is also fully functional and features a built-in stairway where visitors can mail letters of their own."

"The box was built recently on Main Street in Casey (approximate population: 2,700). The box measures 5,473 cubic feet, setting a mark recognized by Guinness World Records. The mailbox is more than a tourist attraction. It’s also functional — customers can mail cards and letters from it," the 21st Century Postal Worker says.

“This is fun for the community and it will be fun for visitors too,” said Casey Postmaster Jeff Donsbach. “We hope the new attraction generates more mail and new revenue.”

"A local company constructed the rural style box, which sits on a wooden structure that resembles a mailbox post. A tube carries the letters from the top of the box to a ground-level point where Postal Service carriers can collect the mail."