No, Percy Jackson: Sea of Monsters was not filmed at Six Flags New Orleans.
While the abandoned theme park is a famously eerie location that has been used for other films and TV shows (like Jurassic World and Deepwater Horizon), the primary filming location for the climactic amusement park scenes in Sea of Monsters was Playland, at the Pacific National Exhibition (PNE) in Vancouver, Canada.
The production did significant set dressing and visual effects to transform the Vancouver location into the “Waterland” amusement park depicted in the film. The final battle with the giant bronze automaton, Talos, was filmed there.
Why the confusion? The confusion likely stems from two factors: 1. Six Flags New Orleans’ iconic look: Its post-Hurricane Katrina decay makes it a visually striking and well-known location for “abandoned theme park” scenes. 2. The film’s setting: Sea of Monsters features a key sequence in a run-down, mysterious amusement park on the coast, which matches the aesthetic of Six Flags NOLA. It’s a natural assumption for fans.
So, while the real Six Flags New Orleans would have been a perfect fit visually, the production chose the practical and film-friendly location in Vancouver for the actual shoot.