He's selling the drawing through Sotheby's, with all proceeds going to Panthera, his wild cat conservation charity.
Video. A rare Rembrandt drawing, Young Lion Resting, could fetch up to $20 million at auction, with proceeds supporting wild cat conservation charity Panthera.
There were no lions in 16th-century Puerto Rico — so was the cave drawing made by someone who'd actually seen one? When you purchase through links on our site, we may earn an affiliate commission.