Over a thousand near-identical hills turn chocolate-brown every dry season

The Chocolate Hills of Bohol, Philippines, are more than 1,000 near-symmetrical, grass-covered limestone mounds spread across roughly 50 square kilometres. Geologists believe they formed from coral deposits pushed up by tectonic movement and shaped by erosion; each dry season the grass covering them turns brown, giving the hills their name.

— Standard geological accounts, Chocolate Hills