Ceded to the Dutch West India Company in 1677 by King Amangkurat I in payment of his debts, it became their headquarters and the seat of the Dutch governor of the northeast provinces. Semarang's usefulness as a port waned due to the gradual silting up of the harbor; by the 19th century, Surabaya had eclipsed Semarang as Java's premier port. With a population of over one million, a third of whom are thought to be of Chinese extraction, Semarang is the largest city in Central Java and its administrative capital. The city consists of two parts: the coastal lowland where most of the commercial activities are found; and the hilly residential area. Although more a business center than a city for tourists, Semarang serves as a popular gateway to the mountainous interior of Central Java and to fabled Borobudur.