All foreign visitors to Tibet require both a Chinese visa and a Tibet Travel Permit, the latter obtainable only through a licensed tour agency — independent travel within Tibet is not permitted for foreigners. Arranging a permit takes at least a week and usually involves booking a guided tour package, even if you want to travel relatively freely once you arrive.
From Lhasa, Shannan/Tsetang is about 180 kilometres southeast along the Yarlung Tsangpo valley. The drive takes three to four hours. Buses run between Lhasa and Tsetang, but most visitors with permits travel by hired vehicle as part of an organised tour. There is a small airport at Shannan (Lhoka Mainling Airport), with limited flights from Lhasa and Chengdu, but most visitors come overland from Lhasa.