The Xiaozhai Tiankeng stands as the textbook example of what happens when karst processes are given perfect working ...

The Xiaozhai Tiankeng, often called the “Heavenly Pit,” stands as the planet’s largest and deepest known sinkhole. This ...

These enormous geoglyphs—etched into Peru’s desert plains—are only fully visible from the sky. Depicting hummingbirds, monkeys, and geometric patterns, the lines have puzzled researchers for decades.