When you want to mail a letter why not in the World's Largest Mailbox in Casey IL (population 2264)

In October 2015, Jim and his team unveiled the world’s Largest mailbox measuring a whopping 162.63 m³ (5,743.41 ft³). A giant version of a standard US mailbox, it has an internal volume of 5,743.41 cubic feet (162.63 m³) and a built-in stairway inside the post stand so that visitors can climb up to the box. Located in Casey’s downtown business district, it’s designed to accept mail (which, when deposited, raises a red flag), and Jim intends to use the interior space to set up a museum of mail history.