Aruba is an island country in the mid-south of the Caribbean Sea, about 29 kilometres (18 mi) north of the Venezuelan peninsula of Paraguaná and 80 kilometres (50 mi) northwest of Curaçao. It measures 32 kilometres (20 mi) long from its northwestern to its southeastern end and 10 kilometres (6 mi) across at its widest point. Together with Bonaire and Curaçao, Aruba forms a group referred to as the ABC islands. Collectively, these and the other three Dutch substantial islands in the Caribbean are often called the Dutch Caribbean, of which Aruba has about one-third of the population. In 1986 it became a constituent country within the Kingdom of the Netherlands, and acquired the formal name the Country of Aruba.