Green orange is a cultivar of citrus fruit similar to an orange, originating in Vietnam. The fruit may be easily recognized by its thick skin, which is typically bright green (because of which, it is sometimes referred to as a green orange), although the skin may also be partly green and partly orange, or entirely orange. Its flesh is orange, dark and sweet. Ham Yen oranges is the best kind oranges and considered one of 50 specialties from Vietnam. They're famous for the sweet, aromatic crispy and high nutritional value.