Bambara people
The general structure of a mask varies depending on the way it is intended to be worn. The most common type applies to the wearer's face, like most Western (e.g., carnival) masks. Others are worn like hats on the top of the wearer's head; examples include those of the Ekhoi people of Nigeria and Bwa people of Burkina Faso, as well as the famous "chiwara" masks of the Bambara people. Some masks (for example those of the Sande society of Liberia and the Mende people of Sierra Leone, that are made from hollow tree stumps) are worn like helmets covering both the head and face. Some African cultures have mask-like ornaments that are worn on the chest rather than the head of face; this includes those used by the Makonde people of East Africa in "ndimu" ceremonies.