Semarang. In the 15th century, the Chinese emperor’s emissary Zheng He, otherwise known as Admiral Cheng Ho. Set foot on Java. From the 17th century onwards, Semarang became an entrepot for spices. Also, a busy harbor for trade and passengers when travel was made predominantly by sea. The city of Semarang, capital of the province of Central Java, sits precisely in the center of the northern seaboard of the fertile and densely populated island of Java.