Rhode Island’s official nickname is “The Ocean State”, a reference to the State’s geography, since Rhode Island has several large bays and inlets that amount to about 14% of its total area. There are 39 cities and towns in Rhode Island. Major population centers today result from historical factors—with the advent of the water-powered mill development took place predominantly along the Blackstone, Seekonk, and Providence Rivers. Providence is the base of a large metropolitan area.