The Mariana Trench is not only deep, it is long, too. It’s 5 x the length of the Grand Canyon or 1,580 miles long (2543 km). At only 43 miles wide (70km), it is also narrow. At the very bottom of the Mariana Trench is Challenger Deep, which is the lowest point on the Earth’s crust.
To understand just how deep that is, let’s compare Mt. Everest at 29,029 feet (8,848 m) above sea level to Challenger Deep. Here we find Challenger Deep is 6,824 feet (2,080 m) deeper than Everest is tall. If Everest were put into Challenger Deep, it would still be over a mile underwater.