In Nujiang, a district of Yunnan near the border with Tibet, muleteers walk along a section of the Tea Horse Road cut into limestone cliffs above the Nujiang River. When Tibetans began drinking tea during the seventh century, the network of routes that linked Yunnan with other parts of Asia gradually became known as the Cha Ma Dao (Tea Horse Road) because it was largely used to exchange Chinese Puer tea for Tibetan war horses. In 1895, a Major Davies, leader of an Indian government expedition, described how the ‘disc-shaped cakes some eight inches [20 centimetres] in diameter and one inch thick, weight about 12 ounces [340 grams]’were‘put together in packets of seven placed one on top of the other, and done up with strips of the outer bark of bamboo’. This organic packaging helped give Puer tea some of its unique flavour as it allowed interaction with rain and microorganisms en route. The tea became so popular that modern processing methods are now used to mimic the fermentation process. The quantities of tea and horses exchanged fluctuated, but records from the end of the 14th century show that the government expected to exchange about half a million kilograms of tea for 14,000 horses, making each animal worth about 56 kilograms of tea. Today, the Tea Horse Road is no longer used to transport tea, but pack animals continue to carry other goods into high-altitude areas that aren’t connected by roads

24 www.geog raphical.co.uk february 2011