Nusantara Day is observed in Indonesia every December 13, commemorating the adoption of the Djuanda Declaration in 1957, which established Indonesia as the world's first archipelagic state. The term "Nusantara," derived from Old Javanese, translates to "archipelago" and historically referred to the territory of the Majapahit Empire. This declaration, articulated by Prime Minister Djuanda Kartawidjaja, defined the waters between Indonesia's outermost islands as internal waters under the country's sovereignty, unifying the nation’s territory for the first time. The principles of Nusantara were later recognized in the United Nations Convention on the Law of the Sea, signed in 1982. This observance highlights Indonesia's unique geographical status as the largest island country, comprising over 17,000 islands, including Java, Sumatra, and Borneo.