The Six Famous Tea Mountains are a set of mountains in S Yunnan, to the east of the Mekong River that bisects the prefecture of Xishuangbana. They got that fame in times of turmoil as Qing took over from Ming, and people and merchants were moving everywheres. Each of the six mountains were named after a symbolic artifact, like a copper gong, or a leather board. People have been harvesting tea from this area for awhile, but it became famous as Han merchants settled in Yunnan, and the Qing accepted tea from Man Song Village's Prince Hill in Yi Bang (wood clapper) as an imperial tribute item. In time, Yi Bang, You Le, Ge Deng, Mang Zhi, Man Sa, and Man Zhuan had all developed tea plantations run either by merchants or the soldiers pacifying the mountainous area. Today, most of these mountains grow rubber (coffee is a growing crop) rather than tea, and few old plantations remain, growing the ancient, small-leaf version of tea. The main Yiwu growing areas are technically on Man Sa, but those plantations use large-leaf, and has been growing that for about 300 years.
Today, as Ge Deng and Mang Zhi doesn't really grow that much tea anymore, You Le and Yi Bang being a bit more successful, people have tried to move the concept of 6FTM to areas all over Bana, like Nannuo or Banzhang. Nobody takes that bit of marketing seriously, though. 6FTM blends, though, are very popular, and they seem to age quite well.