Lhasa lies at about 3,650 metres in a wide, dry valley beside the Kyichu River, and almost every rider who arrives there from the east is a little dizzy from the altitude, a little sunburnt and more than a little humbled. The G318, known as the Sichuan-Tibet Highway, runs over two thousand kilometres from Chengdu, crossing a series of passes above 4,000 metres, plunging through gorges and following the great bend of the Yarlung Tsangpo before it finally settles on this plateau. Reaching the city is the culmination of one of the world's classic overland roads.
Above the town stands the Potala Palace, a thirteen-storey fortress of white and ochre that was rebuilt in the seventeenth century under the fifth Dalai Lama and served as the winter home of his successors until 1959. In the old quarter, pilgrims walk clockwise around the Jokhang Temple, spinning prayer wheels and prostrating themselves on the flagstones, while butter lamps flicker in dark chapels and the air smells of juniper smoke and yak butter. The Barkhor circuit, the lane around the temple, is full of traders, monks, nomads in sheepskins and tourists.
The road itself is hard on both rider and machine. Altitude saps engine power, the weather can switch from sun to sleet in an hour, and landslides, rockfalls and washouts are common, especially in the rainy months. The best time is generally late April to early June, or September and October, when the skies are clear and the barley is golden. Winter brings ice and cold, which makes the high passes dangerous.
There are important rules to know. Foreign visitors need a Tibet travel permit and must travel with an approved guide and a licensed arrangement, and independent riding is generally not allowed. Check current regulations well in advance, since they change and are enforced firmly, and carry all documents for the checkpoints that appear along the route.
In the city, fuel is easy to find, and so is food, from steaming bowls of momo dumplings to butter tea and a sweet milk tea that most visitors come to love. Take it slow for the first two days, drink plenty of water, and respect the altitude, because acute mountain sickness can strike anyone. The thin air has a startling clarity, though, and the sky is a very deep blue.