Here's why:
* Mountains are generally defined as landforms that rise significantly above the surrounding terrain. This definition doesn't inherently exclude areas below sea level.
* The highest point below sea level would be the summit of a seamount or underwater mountain. However, most of these are submerged and not considered "mountains" in the traditional sense.
So, the answer really depends on what you're looking for:
* If you're looking for the highest point on Earth below sea level, it would be the Challenger Deep in the Mariana Trench at approximately 10,924 meters (35,840 feet) below sea level.
* If you're looking for the highest underwater mountain, it would be Mauna Kea in Hawaii. While its summit is above sea level, most of its mass lies beneath the surface.
Ultimately, there's no universally agreed-upon "highest mountain below sea level." It depends on how you define "mountain" and what criteria you prioritize.
