In the scene, at night, in the tent, the production team had manipulated the compass with a magnet, so it could turn sharply as indicated in the script. But strangely, the compass began to do it alone without magnet, and so the scene was filmed, naturally.
Filming the final scenes where the characters, Carlos Puerto (Juan Pablo Olyslager) and Diego (Fabián Sales), appear holding the talk about the mission, both walking to the door of light representing the White City; The shooting took place in the Taulabé caves, Honduras. During the shooting, the heavy truck traffic could be heard inside the cave, which was appealed to the police emergency order to stop traffic. Traffic stopped in sections of 15 minutes among the nation's busiest highway connecting the two most important cities. The generated traffic jam of cars and trucks, was over 3 miles.
During the shooting of the scene in which the four scientists are camping at night and Carlos Puerto hears the voice on the recorder, the production had to cut many times, because they heard several cows, which were next to the set. They kept bellowing for hours. Beside it was a big farm.
During the inspection of locations for placement of equipment, every morning, the production team was afraid to find snakes, which was designated, by chance, a person to go to the front of the group, as bait.