With all of the events and announcements tied to Batman Day, the July 23 celebration of the Dark Knight's 75th anniversary, it's certainly understandable if some slipped through the cracks. Take, for instance, the pictorial postmark (below) offered by the post office in tiny Bat Cave, North Carolina.

To Batman fans disappointed they missed out on the opportunity, Linns.com has some good news: The postmark received a 30-day extension, meaning there's still time to add one to your collection. Requests should be sent to BAT CAVE Station, Box 9998, Bat Cave, NC 28710-9998, July 23. Linns even provides instructions on how to ensure you get the cancellation.

Named after a nearby cave on Bluerock Mountain inhabited by several species of bats, Bat Cave is no stranger to Bat-promotion, as this 1989 newspaper article documents efforts by local businesses to capitalize on the release of Tim Burton's Batman.

"Bat Cave Sign" by Mark Clifton - Own work. Licensed under Creative Commons Attribution-Share Alike 3.0 via Wikimedia Commons