A full-scale model of the Texas was built for the film. After the 1865 sequence was filmed, it was dismantled and reassembled in Morocco.
The only person able to jump from a camel onto a moving train was the camel wrangler himself, therefore, he doubled for all the actors.
Penélope Cruz initially thought she was too young to play a World Health Organization doctor. A real WHO doctor told her that doctors that go to dangerous locations are more likely to be young.
The interior of Massarde's toxic waste disposal plant was the factory in Britain where the jet engines for the Concorde were tested.
The cast had camel-riding lessons during which they would have to ride the camel at full gallop for 90 minutes alongside a moving train.
Breck Eisner: [Falling, swooping objects] This occurs several times throughout the film - during the well scene with Eva Rojas's chemical flare and her associate's hat, as well as the helicopter landing pad light during the fistfight atop Massarde's solar energy plant.