Share: On Aug. 21, 1911, the “Mona Lisa” disappeared. The Italian painting vanished on a Monday morning between 7 and 7:30 a.m. when the Louvre, the Parisian museum where Leonardo Da Vinci’s art piece was being kept, was closed to the public. Only 12 people were at the museum that day, mainly maintenance staff and curators, plus the thief. Follow: