Khun Sa Old Camp is a small, rough museum in the hills north of Mae Salong, connected to the former opium warlord Khun Sa. It is a specialist stop, but it adds a darker counterpoint to the tea plantations and Kuomintang memorials that usually frame the area.
Expect basic interpretation and limited English. Visitors may need a local guide or advance help to unlock the buildings, so treat it as a planned side trip rather than a place to wander into unannounced.