This image grab taken from AFPTV footage shows two environmental activists from the collective dubbed "Riposte Alimentaire" (Food Retaliation) gesturing as they stand in front of Leonardo Da Vinci's ...

You may have seen the Mona Lisa on coffee mugs, phone cases, textbooks, and museum walls, but Leonardo da Vinci’s painting still holds a number of mysteries that were uncovered only in recent decades.

PARIS (AP) — The “Mona Lisa” has given up another secret. Using X-rays to peer into the chemical structure of a tiny speck of the celebrated work of art, scientists have gained new insight into the ...