Not until the late 19th century did humans learn of the extraordinary art produced by their Ice Age ancestors ... The oldest representational cave painting dates from about 30,000 years ago.

Still, accurately dating cave paintings is a difficult task. The pigments used to create them, typically iron oxides like hematite ... an attempt to determine the age of the hand paintings.

Archaeologists discovered ancient Roman inscriptions and a 1,900-year-old coin wedged between rock formations while exploring ...