Durham is a city in the U.S. state of North Carolina. The U.S. Census Bureau estimates the city's population to be 245,475 as of July 1, 2013. Durham is the core of the four-county Durham-Chapel Hill Metropolitan Area. which has a population of 534,578 as of U.S. Census 2013 Population Estimates. The US Office of Management and Budget also includes Durham as a part of the Raleigh-Durham-Chapel Hill Combined Statistical Area, which has a population of 2,037,430 as of U.S. Census 2013 Population Estimates. It is the home of Duke University and North Carolina Central University, and is also one of the vertices of the Research Triangle area (home of the Research Triangle Park).