How exactly does the Eiffel Tower maintain its clean look? With 66 tons of lead-free paint http://on.natgeo.com/2p5Z0Qv

How exactly does the Eiffel Tower maintain its clean look? With 66 tons of lead-free paint http://on.natgeo.com/2p5Z0Qv 

https://twitter.com/NatGeoTravel/status/860623149691543553