You cannot take a firearm aboard an airplane in the U.S. in your carry-on or on your person, unless you are a specially licensed law enforcement official. More than a decade after 9/11 and with restrictions on everything from water bottles to deodorant, that may seem like common sense by now.

Apparently not to nearly 2,000 travelers last year alone - including one guy that tried to hide a shotgun in a golf bag.

According to a yearend review blog post by the Transportation Security Administration, 1,813 firearms were found in carry-on bags or on travelers at checkpoints at 205 airports in the U.S., "averaging nearly five firearms per day." Eighty-one percent of which, the TSA said, were loaded.

So which airports saw the most firearms on their x-ray screens in 2013? According to the TSA…

1. Hartsfield-Jackson Atlanta International Airport with 111 guns

2. Dallas Fort Worth International with 96 guns

3. George Bush Intercontinental Airport (Houston) with 68 guns

4. Phoenix Sky Harbor International Airport with 66 guns

5. Denver International Airport with 51 guns

Guns weren't the only surprisingly and potentially terrifying discoveries made by the TSA. In March an officer discovered a very convincing fake suicide vest at Indianapolis International Airport. It turned out the vest belonged to an explosives instructor. There were also an inordinate amount of ninja stars confiscated over the last year.

So before you attempt to travel with your favorite deadly weapon in 2014, maybe brush up on the TSA's list of prohibited items.