Art connoisseurs flock to Paris' Louvre to see iconic works like the "Mona Lisa." However, many other less-crowded historic pieces are worth checking out.

While the film's mystery unravels, the Mona Lisa sits on the sidelines ... where his latest endeavor is implementing a new alternative energy source he calls Klear, though it's never been tested.

Paris' centuries-old Louvre Museum — home of da Vinci's iconic Mona Lisa — is getting an $800 million makeover, and American visitors will have to help pay for it.