Number 1 Due to the absence of actual soil in the Canyon, very little plant life can grow on the floor, except for desert plants.
Number 2 The oldest human artifacts in the Grand Canyon are estimated to be 3000-4000 years old.
Number 3 On average, it is 5000 feet deep (1,524m or over half a kilometer deep
Number 4 Its base is about 1/3 of the earth's age.
Number 5 It is the third largest canyon in the world (exceeded by Barranca de Cabre in Northern Mexico and Hell's Canyon in Idaho).