The high western mountains, inhabited by numerous hilltribes, were until quite recently pretty wild spots but are better known today for trekking, royal projects and coffee and tea plantations rather than opium, while Burmese border crossing Mae Sai’s main contemporary illicit trade is in dodgy Chinese goods, duty-free cigarettes and fake Viagra. Plenty of illegal drugs still do flow over the Burmese border – principally methamphetamines these days – and rural Chiang Rai sees more police road blocks than just about any other northern province.