Native to the Indonesian portion of Borneo, Kastooree mangoes are mostly round with a skin that turns a deep purple to almost black color when mature. As a matter of fact, the skin color is not the only thing that makes Kastooree stand out when gathered with other mangoes, but the taste itself is said to be more intense than the common mangoes, considering this variety has a distinct flavor. In addition, Kastooree mangoes are high in fiber, and in vitamins A and C. Besides, they have several qualities that make them excellent for digestive health.