Kayan People Of Chiang Rai Mai, Thailand.
Immigrating from Myanmar and seeking refuge in the hillside region of Chiang Rai Mai, Thailand, the female members of the Kayan (or long-neck) tribe are renowned for wearing brass rings around their necks, starting at the age of four and consecutively adding more and more rings as they grow older.
Exploring local legend, it has been said that a great tiger once invaded their village and killed the majority of the women from their tribe while the men were away by biting them on the neck. In an effort to defend against potentially fatal future attacks, the women began wrapping brass rings around their necks, should the tiger ever return. Slowly, however, the rings transitioned away from being a thing of utility and into a mark of beauty.
Interestingly enough, the rings do not actually aid in the extension of the neck; rather, depress the shoulders to give the illusion of a longer neck.