The controversial new railroad between Beijing and Lhasa, capital of Tibet, travels over some of the highest terrain in the world. At over 16,000 feet the oxygen content is just 45% of normal levels, and oxygen masks are supplied for passengers. John Flinn of the San Francisco Chronicle rode the train and filed an illustrated report in the November 5, 2006 Sunday issue.
More recently the New Yorker (April 16, 2007) published a longer article by Pankaj Mishra. It describes the author's train ride to Lhasa and ponders the political implications of the new rail link. An abstract is available.