San Antonio is the second-largest city in the state of Texas and the seventh-largest city in the United States with a population of 1.4 million. The city is the seat of BexarCounty. The city was named for the Portuguese St. Anthony, whose feast day is on June 13, when a Spanish expedition stopped in the area in 1691. San Antonio has a diversified economy with four primary focuses: financial services, government, health care, and tourism. Located northwest of the city center is the South Texas Medical Center, which is a conglomerate of various hospitals, clinics, and research and higher educational institutions. The city is also home to one of the largest military concentrations in the United States.