Situated on the borders of Bexar and Comal County, San Antonio is the second largest city in Texas and is one of the top fifty cities in population size in the United States. The metropolitan area of the city has an estimated two million residents and is the fifth fastest growing large city in the country. Home to Fort Sam Houston, Brooks City-Base, Camp Bullis, the Lackland Air Force Base and the Randolph Air Force Base, San Antonio is well known as strong military supporting city. It is also known for attracting tourists and families as well with a Six Flags Fiesta Texas theme park, Sea World park, and the historic Alamo. According to the local Visitors Bureau, the city is visited by 26 million tourists per year. The town is also home to professional sports teams such as the San Antonio Spurs. Being a very large city, San Antonio is covered entirely by the area code 210, but has many zip codes from 78201 all the way to 78299.