Hùizhōu (Chinese: 惠州), historically known as Waichow, is a city located in central Guangdong province of the People's Republic of China. Part of the Pearl River Delta, Huizhou borders the provincial capital of Guangzhou to the west, Shaoguan to the north, Heyuan to the northeast, Shanwei to the east, Shenzhen and Dongguan to the southwest, and looks out to the South China Sea to the south. Administered as a prefecture-level city, it has 4,60 million residents in its area of jurisdiction. Its southern part made of Huiyang district is now part off guangzhou-Shenzhen built up area, the biggest built up area in the world with more than 40 million inhabitants encompassing the whole Shenzhen, Dongguan cities and main part of Guangzhou, Foshan, Zhongshan and small parts of Jiangmen and Huizhou cities. There are two main dialects spoken by local people in Huizhou: Hakka (客家话/客家話) and a Cantonese dialect which is Huizhouhua (惠州话/惠州話). The two dialects are somewhat interrelated and similar so people can easily understand each other. As more newcomers from the other provinces come to work in Huizhou, Mandarin has become the other popular language in Huizhou.