The X marks the spot in Wakulla Springs, Florida.
And remember this one for your next trivia night: What movie starred Maid Marion, a Friend of Harry Lime, Kolchak the Night Stalker, Buck Rogers, Count Dracula, Ensign Pulver, sudsy Felicia Karpf, Johnny Bravo's Mom, Rage'n Rob Verne, Professor Eggstrum, Detective Ed Hocken, one of the Wild Women of Chastity Gulch, the Man Who Shot Liberty Valance, the Man Who Tried to Shoot Navin Johnson, and the Bermuda Triangle. And the only thing more amazing than that all-encompassing cast is the amount of property damage they caused, chewing on all the furniture inside that poor airplane.
FYI: Airport, Airport '75 and Airport '77 are currently available for streaming on Netflix. Please note the absence of Concorde: Airport '79, as I'm sure it's inclusion for viewing would cause more customers to drop the service than that ridiculous price hike last month.