Four separate and distinct state universities are located in Houston. The University of Houston is a nationally recognized Tier One research university, and is the flagship institution of the University of Houston System. The third-largest university in Texas, the University of Houston has nearly 40,000 students on its 667-acre campus in southeast Houston. The University of Houston–Clear Lake and the University of Houston–Downtown are stand-alone universities; they are not branch campuses of the University of Houston. Located in the historic community of Third Ward is Texas Southern University, one of the largest historically black colleges and universities in the United States.