Charango

A charango is a South American stringed instrument of the lute family with the back of an armadillo. It has five pairs of strings tuned EAECG.

http://comunidad.ciudad.com.ar/ciudadanos/trazom/Folklore/Instrumentos%20Musicales/Charango/charango.htm

http://www.ancient-future.com/guitar/charango.html

http://www.frii.net/~brain/charango/