The Golden Triangle takes part of its name from its location on the border of three countries: Thailand, Myanmar, and Laos. Gold refers to "black gold" – or opium – which has contributed to the wealth of the region since it was first produced there in the 19th century. The CIA popularised the name Golden Triangle in the 1970s, when drug trafficking reached its peak. Nearly 700 tonnes of opium were produced every year in the region and exported worldwide. It was often sold as heroin. But the region has seen a rise in new illicit synthetic drugs such as methamphetamine and ketamine. They are manufactured in secret laboratories in Myanmar. The Golden Triangle drug cartels, allied to the powerful Chinese mafia, now produce more methamphetamine than their counterparts in Mexico. It’s a huge illegal industry that helps fund the civil war in Myanmar that began after the military coup in 2021. Constantin Simon, Aruna Popuri, William de Tamaris and Justin McCurry report on this deadly trade.