Leaving Song Kul we make our way back over the mountains heading southwards towards the Chinese border. For our final night in Kyrgyzstan we are staying in yurts at Tash Rabat before crossing the Torugart Pass. Tash Rabat is a Silk Road monument par excellence: a small but perfectly formed 15th-century caravanserai that sheltered an array of merchants and travellers along one of the wilder stretches of the Silk Road.