What is an on-top-of-the-world mountain?

A mountain is “on top of the world” (OTOTW) if nothing on Earth rises above the horizon of an observer at its summit, considering that distant terrain dips below the horizon due to Earth’s curvature. OTOTW mountains often have expansive views and dominate over their surroundings.

The horizon is defined as the flat plane that intersects the summit and is perpendicular to the direction of gravity. “Above the horizon” means on the side of this plane opposite the direction of gravity.

K2, the second-highest mountain on Earth, is OTOTW. Despite Mount Everest being higher, it is well below the horizon of K2’s summit due to Earth’s curvature.

Click on a mountain on the map to view its following metrics:

• Jut: a measure of a mountain’s impressiveness, considering its height above immediate surroundings and steepness. Mountains on this map are color-coded by jut, as it provides a better indicator of the impressiveness of the summit views than elevation or prominence. Detailed explanation of jut.
• Dominance: a measure of a mountain’s height above its large-scale surroundings.
• Elevation: a mountain’s height above sea level.
• Prominence: a mountain’s independent rise. Mountains on this map have a prominence of at least 300 meters.

Fun facts about OTOTW mountains:

• Before widespread exploration and accurate measurements, many OTOTW mountains were mistaken to be the highest in the world. Such mountains include Mount Olympus, Mont Blanc, Chimborazo, Nanda Devi, Dhaulagiri, Kangchenjunga, and K2.
• In Colorado, there used to be contention on whether Mount Elbert or nearby Mount Massive was higher. Part of the reason could be that both mountains are OTOTW. Standing atop Elbert, it feels like you’re higher than Massive, and standing atop Massive, it feels like you’re higher than Elbert.

This map is made possible with Andrew Kirmse’s work in identifying every mountain worldwide, as well as the Copernicus GLO-30, ALOS World 3D-30m, and MERIT digital elevation models, the EGM2008 geoid model, and Google Earth Engine. This website, as well as the concept of an OTOTW mountain, is developed by Kai Xu.

This research paper provides more information on OTOTW mountains, as well as jut and dominance.

Download CSV file of OTOTW mountains.

For any inquiries, please email Kai Xu at [email protected].