On July 20, 1969, Apollo 11 astronauts Buzz Aldrin and Neil Armstrong landed their moon module on a broad dark lunar lava flow, called the Sea of Tranquility. And six hours later, Neil Armstrong became the first human being to walk on the surface of a world beyond Earth. Altogether, Armstrong and Aldrin spent 21 1/2 hours on the moon’s surface. Finally, they returned safely to Earth and landed in the Pacific Ocean on July 24, 1969.

Source: EarthSky