BBC - Travel - The haunting Sichuan-Tibet Highway

“Double rainbow!” a passenger on the bus yelled. “Look to the left!” We were somewhere in the Hengduan Mountains that stretch across the western portion of China’s Sichuan. Below us, twin kaleidoscopes of colour hung above a rushing gorge, hundreds of meters below.Related slideshow: World's most treacherous roadsThe sight was a bright spot on what had thus far been a punishing journey through one of the world’s most remote regions.