Despite recent and rapid economic progress, CHIANG MAI - Thailand's second city - manages to preserve some of the atmosphere of an overgrown village. The old quarter, set within a two-kilometre-square moat, has retained many of its traditional wooden houses, and inviting guesthouses, good markets and plenty of sights make it a hugely appealing place to many travellers. Plus, of course, Chiang Mai is the main centre for hilltribe trekking.