Columbia is the fifth-largest city in Missouri, and the largest city in Mid-Missouri. With a population of 110,438 as of the 2011 according to the United States Census, it is the principal municipality of the Columbia Metropolitan Area, a region of 175,831 residents. The city serves as the county seat of Boone County and as the location of the University of Missouri. The college town is politically liberal and is known by the nicknames “The Athens of Missouri,” “College Town USA,” and “CoMO.