Wikipedia
Bordonua
The Bordonua (Bordonúa) is a large, deep body (sound-boxes are usually deep) bass guitar which is native to Puerto Rico. They are made using several different shapes and sizes.
The Bordonúa is the least common of the three stringed instruments that make up the Puerto Rican orquesta jibara (i.e., the Cuatro, the Tiple and the Bordonúa).
The Bordonua usually has 3 sound holes, with a large central one and two smaller ones in the two corners of the upper bout. The usual body shape is quite slender and tapers in towards the top, however there is a wide variety of other designs also.