“Airport.”
Most airport ticketing and baggage claim areas are open to the public and a gun could easily be brought in...whether legal or not.
But, it doesn’t really matter. They could have security checks at the interstate off-ramps or other streets entering an airport...and someone would open up on folks at that point. Heck...at my local airport, bad guys could just spray the crowd collecting at the TSA security check-thru past the ticketing area.
Unarmed is unarmed.
An airport is a classic place to not bring a gun, especially if traveling.