While the common perception of the Golden Triangle (which traditionally defined as covering northern Thailand, eastern Burma and the west-most portion of Laos) among travelers is that of a sense of danger on the off-beaten path, these days, those areas are filled with quaint and quite lovely sights.
In Thailand especially, many of the towns here have traded in the opium trade for hotels—something a little quieter, and more legal. With tons of places to go see in the Golden Triangle, Mai Sai is one of the more popular options. Just a quick hop from Chiang Rai or Chiang Mai, the only thing separating you from Burma is a quiet stream that partitions the two countries.
For a little more punch, all signs on the opium trail lead to Chiang Rai, where you can take on the brooding ruins of Chiang Saen , once home to King Mengrai, or head down to the weekend night market for a very cheap and negotiable shopping experience.
From here you can head west to take in some of the more localized sites, in the growing villages of the Karen, Yao Lahu, or Akha, Lisu, Shan. Be careful though, no cars will be around to bring you to and back, the only way into these villages is either by elephant or on the back of the mule—rides that yield some wonderful photo opportunities.