For most, Everest is considered the highest mountain in the world. If you measure its height above mean sea level, then the Everest of 8,849 meters, which straddles the border between Tibet and Nepal, is indeed the highest in the world.

However, if you measure a mountain from its base to its summit, then Everest is not the highest. It’s the Mauna Kea 10,211 meters long, an inactive shield volcano on the island of Hawaii, CNN reports.

But there is one more mountain in the running for the tallest: Mt Chimborazo, an inactive stratovolcano in the Cordillera Occidental mountain range of the Andes of Ecuador.

When measured from sea level, Chimborazo is about 2,590 meters shorter than Mount Everest. However, its summit is actually 2,072 meters further from the center of the Earth, making it the closest point on Earth to the stars.

“If you imagine the Earth as this blue dot in space, it’s the only place you can stand and be as far away from the center of that dot as possible,” explains Derek van Westrum, a physicist with NOAA’s National Geodetic Survey.

The reason lies in the location of Chimborazo, which is 1.5 degrees south of the equator.

Van Westrum explains that the planet actually protrudes a bit around its waist. “The Earth is made of rock and is quite round, but because it rotates, it bulges at the equator,” he says.

The centrifugal force created by the planet’s constant rotation squeezes the rock, and Chimborazo takes advantage of this swirl to lie further from the center of the Earth than mountains higher than sea level in the Himalayas – or even the Andes – all of which are further away from the equator.

Chimborazo is only the 39th highest mountain in the Andes when measured from sea level, but there was a brief period in the 19th century when it was thought to be the world’s highest peak.

This reputation originated with the influential German geographer and explorer Alexander von Humboldt, who climbed Chimborazo in 1802. Von Humboldt only reached 19,300 feet before descending into the highland valley he would later call the Avenue of Volcanoes.