* At the downstream end of the Gorge there still is a sign saying No Foreigners Allowed.

* On the far side of Jari Hill rises another tiny stream – the declared headwater of the Mekong.

* And 300 miles short of Tiger Leaping Gorge, which all had said was the most dangerous stretch of the river.

* Since Eocene times India has ploughed nearly a thousand miles northward, and it is still heading that way at two inches a year – enough of a velocity (nine times the rate of fingernail growth) to impose enormous stresses, and to trigger the devastating earthquakes – like that of October 1995 – that plague the chaotic countryside of Yunnan and the Burmese border.