Monrovia lies along the Cape Mesurado peninsula, between the Atlantic Ocean and the Mesurado River, whose mouth forms a large natural harbor. The Saint Paul River lies directly north of the city and forms the northern boundary of Bushrod Island, which is reached by crossing the "New Bridge" from downtown Monrovia. Monrovia is located in Montserrado County and is Liberia's largest city and its administrative, commercial and financial center.