Mount Everest rises higher above sea level than any other mountain on the planet.

The longer version

Height above sea level is measured from a shared baseline rather than from the base of the mountain itself. Peaks standing on high plateaus start from ground that is already far above the sea, which helps them claim the top spot. Surveyors use satellite readings and careful ground measurements to fix the figure, and small revisions happen as techniques improve.

Other claims exist for the title of tallest. A volcano measured from its underwater base, or a peak measured from its own foot, can outrank Everest under those definitions. What makes the mountain notable is the thin air near its summit, where oxygen pressure drops far below what human bodies tolerate.

Where this entry sits

These facts wander across maps, borders, deserts, rivers, mountains, and the extreme corners of the natural world. Each one is short and self-contained, offering a small surprise about places you may never visit rather than anything you actually need. The full list sits on the Geography page, where every entry is listed in order.