Mysterious secret tunnels sketched by Leonardo da Vinci 530yrs ago may have finally been uncovered under medieval castle / Thomas Edison, Albert Einstein and Leonardo da Vinci all talked to themselves -- here's why self-blather might help us in these dark times / Rare Renaissance Portrait--Once Attributed to Leonardo da Vinci--Sets $3.1 Million Record / Leonardo da Vinci's secret underground tunnels discovered after 500 years / Leonardo da Vinci Described Secret Passages in Sforza Castle. High-Tech Analysis Just Proved Him Right / Underground passages cited by Leonardo da Vinci discovered beneath Milan's Sforza Castle / Leonardo da Vinci's Surreptitious Scents / Ken Burns takes 4 hours to canonize Leonardo da Vinci. He needed only two. / Artist, scientist, polymath -- a new documentary uncovers the real Leonardo da Vinci / Ken Burns on Leonardo da Vinci: 'He may be the person of the last millennium'