"Mount Everest is usually said to be the highest mountain on Earth. Reaching 29,035 feet at its summit, Everest is indeed the highest point above global mean sea level—the average level for the ocean surface from which elevations are measured. But the summit of Mt. Everest is not the farthest point from Earth’s center.
Earth is not a perfect sphere, but is a bit thicker at the Equator due to the centrifugal force created by the planet’s constant rotation. Because of this, the highest point above Earth’s center is the peak of Ecuador’s Mount Chimborazo, located just one degree south of the Equator where Earth’s bulge is greatest. The summit of Chimborazo is 20,564 feet above sea level. However, due to the Earth’s bulge, the summit of Chimborazo is over 6,560 feet farther from the center of the Earth than Everest’s peak. That makes Chimborazo the closest point on Earth to the stars.
You may be surprised to learn that Everest is not the tallest mountain on Earth, either. That honor belongs to Mauna Kea, a volcano on the Big Island of Hawaii. Mauna Kea originates deep beneath the Pacific Ocean, and rises more than 32,800 feet from base to peak."
Via Seth Dixon