The Mende  people of Sierra Lone are best known for helmet-shaped masks, named sowei or bundu. These masks are used by the sande society during the initiation of girls.

Mende are organized into various social structures, such as firmly marked kin groups, political hierarchies and societies for diverse purposes: training boys and girls in appropriate behavior, protection against enemies or curing illnesses. 

All Mende girls join the sande society at puberty. During the process of initiation, they learn wisdom, beauty, grace, and self-control, all of which they will need within the multi-generational, polygamous households of their future husbands. 

Representing female water spirits, the masks have an idealized female face whose aesthetic reflects religious and philosophical ideals. The design of the facial features conforms to strict conventions and has symbolic content. The masks are carved by men, but danced by women. This is unusual in Africa.