The vertical glass map of Isla Nublar was used to keep track of the locations of the dinosaurs in the park. The computer system was also able to show the past movements of the animals. It could also show the location of every animal in the park, accurate to about five feet. John Arnold used the map to show the locations and past movements of both the juvenile and the adult Tyrannosaurus Rexes. The map was used to showcase the park’s security system to visitors Donald Gennaro, Dr. Alan Grant, and Ian Malcolm, who were evaluating the park and testing it for potential problems.