First time humans walked on the moon.
First words spoken from the surface of another world: "Houston, Tranquility Base here. The Eagle has landed."
A plaque on the descent stage (which also served as launch platform for the ascent stage and remains on the lunar surface) reads: "Here men from the planet Earth first set foot on the moon July 1969, A.D. We came in peace for all mankind."
To make the lander as light as possible, it contained no seats. The astronauts stood while descending to the lunar surface and returning to the orbiting command module.
The command module was named "Columbia" after "Columbiad," the canon that launched the moonship in Jules Verne's novel, From the Earth to the moon.