Macao has generally flat terrain resulting from extensive land reclamation, but numerous steep hills mark the original natural land mass. The modern high-rise skyline of Macau obscures much of the hilly landscape.
Macao is essentially urban; an area of land reclaimed from the sea measuring 5.2 sq km and known as Cotai now connects the islands of Coloane and Taipa; the island area is connected to the mainland peninsula by three bridges. The region comprises the Macao Peninsula and the islands of Taipa and Coloane. Macao was once an island but gradually a connecting sandbar turned into a narrow isthmus. Land reclamation in the 17th century made Macau into a peninsula, and a barrier gate was built to mark the separation between the peninsula and the mainland.
Macao is located at the south of Guangdong Province, on the tip of the peninsula formed by the Zhujiang (Pearl River) estuary on the east and the Xijiang (West River) on the west. Macao is situated 60 km (37 mi) west of Hong Kong, and 145 km (90 mi) southwest of Guangzhou, the capital of Guangdong Province. It is situated immediately east and south of Zhuhai.