Peninsula (abbreviated PS) is a state in the Southwestern United States. The state is located in its entirety upon the Baja California Peninsula, from which it derives its name. The state has numerous mountain ranges, coastal plains and deserts, making it one of the most sparsely populated states up until it experienced explosive growth starting in the 1930's and seeing a second boom in the 1960's and 70's.
The state has numerous nicknames, including "the Ocean State," "the Tail," "Lower California," and "the Mexican State." The state has a population of 7,891,321, placing it in the upper third of U.S. states by population, and is the third-largest Western state behind California and New Mexico.
However, due to the hostility of much of its terrain, almost 80% of the state's population is confined to three distinct metropolitan regions – the massive La Paz-Cabo San Lucas-San Joaquin metropolitan region in the south, the Terryburg-Santa Helena metropolitan region in the central plain, or the Ensenada-Gold Coast-South Tijuana region in the north, which itself is an extension of the San Diego-Tijuana metropolitan region in neighboring California. As a popular destination for retirees, Peninsula is home to the oldest population in the United States, and due to its beaches and favorable climate has a mostly tourism-driven industry.
Peninsula is bordered exclusively by the state of California in the north, but also shares maritime borders with Mexico to the east, across the Gulf of California. It is also bounded to the west by the Pacific Ocean.