The area around Nan is an insider tip for Thailand travellers. There are lots of interesting and well-surfaced roads around with very little traffic. The road from Pua over Doi Phu Kha (1653m according to my GPS, 1684m according to the sign) to Bo Kluea is probably one of the nicest, if not THE best around. Near the top of the pass there is an interesting shrine and in Bo Kluea there are some interesting salt works to visit. For some pictures see the end of this page: http://sites.google.com/site/beddhist2/t9
Beddhist