Chios is the capital of the province and has about 25,000 inhabitants. The city is a bustling port and commercial center. In the center of town stands the Byzantine museum with a variety of historical artifacts from the island's past. Modern Chios has been built on the site of the ancient city from which there exist a few survived findings – in particular the walls and the theater. The Castle is quite impressive. Originally built by the Byzantines as a fortress, it was significantly extended by the Genovese in the 14th century.