Houston is the largest city in the state of Texas, the fourth-largest in the United States. As of the 2005 U.S. Census estimate, it had a population of more than 2 million. Houston's economy has a broad industrial base in the energy, aeronautics, and technology industries and only New York City is home to more Fortune 500 headquarters. Houston is a multicultural city with a large and growing international community. The Museum District is home to many cultural institutions and exhibits, attracting more than 7 million visitors a year.