Planet of the Apes Franklin J. Schaffner

Astronauts Taylor, Landon, and Dodge awaken from deep hibernation after a near-light-speed space voyage. Their spacecraft crashes into a lake on an unknown planet; Taylor's estimate places them in Orion's Bellatrix System, 300 light-years from their home Solar System. Before they abandon their sinking vessel, the three survivors read the ship's chronometer as November 25, 3978 – two thousand and six years after their departure in 1972. However, due to time dilation, the astronauts themselves have aged slightly less than one year.

The men travel through desolate wasteland, coming across eerie scarecrow-like figures and a freshwater lake with lush vegetation. While the men are swimming, their clothes are stolen and shredded by primitive mute humans. Soon after, armed gorillas raid a cornfield where the humans are gathering food. Taylor is shot in the throat as he and the others are captured. Dodge is killed and Landon is rendered unconscious in the chaos. Taylor is taken to Ape City. Two chimpanzees, animal psychologist Zira and surgeon Galen, save Taylor's life, though his throat injury renders him temporarily mute.

Taylor is placed with a captive female, whom he later names Nova. He observes an advanced society of talking apes with a strict caste system: gorillas are the military force and laborers; orangutans oversee government and religion; and intellectual chimpanzees are mostly scientists and doctors. The ape society is a theocracy, while the apes consider the primitive humans as vermin to be hunted and either killed outright, enslaved, or used in scientific experiments. Taylor convinces Zira and her fiancé, Cornelius, that he is as intelligent as they are by making a paper airplane. Dr. Zaius, their orangutan superior, arranges for Taylor to be castrated against Zira's protests. Taylor escapes and finds Dodge's stuffed corpse on display in a museum. He is soon recaptured, in the process revealing that he can speak, which alarms the apes.

A hearing to determine Taylor's origins is convened. Taylor mentions his two comrades, learning that Landon was lobotomized and rendered catatonic. Believing Taylor either is from an unknown human tribe beyond their borders or was the subject of a mad scientist who gave him the power of speech, Zaius privately threatens to castrate and lobotomize Taylor for refusing to reveal his origins. With help from Zira's nephew Lucius, Zira and Cornelius free Taylor and Nova and take them to the Forbidden Zone, a taboo region outside Ape City where Taylor's ship crashed. Ape law has ruled the area out of bounds for centuries. Cornelius and Zira are intent to gather proof of an earlier non-simian civilization – which Cornelius discovered a year earlier – to be cleared of heresy; Taylor focuses on proving he comes from a different planet.

When the group arrives at the cave, Cornelius is intercepted by Zaius and his soldiers. Taylor holds them off by threatening to shoot Zaius, who agrees to enter the cave to disprove their theories. Inside, Cornelius displays remnants of a technologically advanced human society pre-dating simian history. Taylor identifies artifacts such as dentures, eyeglasses, a heart valve, and, to the apes' astonishment, a talking human doll. Zaius admits he has always known about the ancient human civilization. Taylor wants to search for answers. Zaius warns Taylor against finding an answer which he does not like, adding that the now-desolate Forbidden Zone was once a lush paradise. After Taylor and Nova are allowed to leave, Zaius has the cave sealed off to destroy the evidence, while charging Zira, Cornelius, and Lucius with heresy.

Taylor and Nova follow the shoreline on horseback. Eventually, they discover the remnants of the Statue of Liberty, revealing that this supposedly alien planet is actually Earth, long after an apocalyptic nuclear war. Understanding Zaius' earlier warning while Nova looks on in shock, Taylor falls to his knees in despair, cursing humanity for destroying the world.