On what planet does “Planet of the Apes” take place?
After landing on what they think is an alien planet in the year 3978, a group of astronauts begins to explore the unfamiliar terrain. They find a civilization of intelligent, speaking primates that run the planet. Eventually, one of the astronauts, Taylor (played by Charlton Heston), is banished to the Forbidden Zone, where he discovers the remains of the Statue of Liberty, proving that they were on Earth all along.
The correct answer is Earth.