Just finished Peter Hopkirk's Trespassers on the Roof of the World: The Race for Lhasa, a history of early western travellers who tried (and mostly failed) to reach Tibet's mysterious capital.
The manic determination of a seemingly endless line of British, French, Russian and American adventurers, as well as the inevitable Jesuits, is well told. All got turned back or died along the way... until a Japanese abbot got there in 1901 (doesn't really count?), followed by Francis Younghusband and army who entered the city by force in 1904.
Despite its allure, many were rather disappointed by what they found. Apart from the Potala, most of the city was ramshackle, its inhabitants living in squalor.
One niggle: the book starts in the 1860s and therefore misses out much that happened before, including another earlier envoy, George Bogle, who spent time in southern Tibet in the 1770s (although to be fair, he wasn't particularly aiming for Lhasa). But the real omissions are the much earlier travels of Jesuit priests like Johann Grueber & Albert d'Orville who reached Lhasa in 1661, and Ippolito Desideri & Manoel Freyre in 1716. I'm no expert but I read about them this summer (see post). Hopkirk's book was published 30 years ago so maybe their exploits only recently came to light?