Tuva or bust .. Richard Feynman “1988 BBC ‘Horizon’ documentary on the Noble Prize winner Richard Feynman and his attempt to visit Tannu Tuva.” (YouTube, 45min)
Sadly, Feynman didn’t make it to Tuva because he passed away from cancer, but his friend Ralph Leighton went on the trip they planned together. Later, Feynman’s daughter Michelle also visited Tuva. Leighton founded the Friends of Tuva. The website is a bit outdated by now, but still contains a lot of interesting information and links.