You’ve probably heard of adventurers skiing down the highest mountain in the world. But did you know that elite cyclists can actually ride up it in a day’s time? Then race down at 80 miles per hour?

You probably guessed that I’m not talking about Everest. It’s still the tallest when measuring purely by height above sea level, or altitude, at just over 29,000 ft.

But by other metrics, there are other contenders.

If you measure from the center of the Earth, the highest mountain is near the equator, where the Earth is 21 km wider than at the poles. By this measure, the tallest is the volcano of Chimborazo, in Ecuador.

But, if you’re starting at the base of the mountain and measuring to the top, the tallest—by a wide margin—is another volcano: Mauna Kea on the big island of Hawaii.

Its summit is just shy of 14,000 ft above sea level, the ocean around Mauna Kea is almost 20,000 ft deep, and the base of the volcano is on the seafloor. This makes Mauna Kea nearly 34,000 ft from tip to toe, a full mile taller than Everest.

Its low humidity and long distance from civilization make Mauna Kea an excellent astronomical observatory, with 13 international telescopes at its summit.

There are roads leading up to them, so if you’re looking for an 8-hr-straight-up bike climb followed by a blistering white-knuckle descent, Mauna Kea may be your kind of mountain.