Tibet tops many travellers dream lists. Days 1-2, Lhasa: after acclimatising, visit the Potala Palace (book ahead) and Jokhang Temple, walk the Barkhor pilgrimage circuit, sip sweet tea and watch the crowds.
Day 3, around Lhasa: Norbulingka Palace, the debating monks at Sera Monastery, or the impossibly blue Yamdrok Lake.
Days 4-5, Nyingchi: in late March-early April the peach blossom festival covers the valleys; the Yarlung Tsangpo Grand Canyon and misty Namcha Barwa peak; green-jade Basum Lake.
Day 6, return to Lhasa or fly out. Nyingchi lower altitude (about 3,000 m) makes it a good buffer for acclimatisation.
Notes: altitude sickness varies by person - avoid strenuous activity and alcohol the first two days; some areas require a border permit; Potala tickets in peak season need booking 3-7 days ahead on official channels.
Respect local customs: walk the kora clockwise, do not photograph statues, remove hats in monasteries.